Protesters march along Whitehall toward parliament, with Nelson's Column in the background, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

A cutout of David Attenborough is held up as protesters march toward parliament with Nelson's Column in the background, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

A cutout of David Attenborough is held up as protesters march toward parliament with Nelson's Column in the background, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Police officers line up near the Houses of Parliament in London, Tuesday April 23, 2019, ahead of climate protesters arriving. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protesters march past Downing Street toward parliament, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

A cardboard cutout of David Attenborough is held up as protesters march toward parliament with Nelson's Column in the background, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters arrive in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

A protester wearing an animal mask arrives with others in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protesters in trees as others arrive in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters arrive in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters arrive in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters sit in the road in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters sit in the road in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters attach models of skeletons to a lamp post in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters attach models of skeletons to a lamp post in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters sit in a road in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protesters hold up models of skeletons in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protesters assemble models of skeletons in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters sit in a tree in Parliament Square, in London, Tuesday April 23, 2019, during a climate protest. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

A cardboard cut-out of David Attenborough is seen during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

A cardboard cut-out of David Attenborough is seen during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protesters attend a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Members of the so called 'Red Brigade' march during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protesters are seen in the trees during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters attend a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protester queue up to hand letters in to Parliament, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protester queue up to hand letters in to Parliament, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Members of the so-called 'Red Brigade' attend a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Members of the so-called 'Red Brigade' attend a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protester queue up to hand letters in to Parliament, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protesters attend a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Alastair Grant)

Protesters and their children take part in activities during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters stand with their hands over their hearts during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters and their children take part in activities during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters attend a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters take part in games during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters take part in games during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters take part in games during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters take part in games during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters climb trees near the statue of Gandhi, during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Labour MP and Shadow Health Secretary Jon Ashworth addresses the crowd during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Protesters attend a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

A protester, with half of her body covered in body paint, faces police during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

A protester, with half of her body covered in body paint, faces police during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

A protester, with half of her body covered in body paint, faces police during a climate protest in Parliament Square, in London, Tuesday April 23, 2019. The non-violent protest group, Extinction Rebellion, is seeking negotiations with the government on its demand to make slowing climate change a top priority. (AP Photo/Matt Dunham)

Climate change activists from the group Extinction Rebellion march down Whitehall as they protest in central London on April 24, 2019 (Photo by ISABEL INFANTES / AFP)

Climate change activists from the group Extinction Rebellion march down Whitehall as they protest in central London on April 24, 2019 (Photo by ISABEL INFANTES / AFP)

Climate change activists from the group Extinction Rebellion march down Whitehall as they protest in central London on April 24, 2019 (Photo by ISABEL INFANTES / AFP)

Extinction Rebellion climate change activists in red costume walk along Whitehall in Westminster, London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

An activist climbs a tree during the ongoing Extinction Rebellion climate change demostration in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Labour MP Jon Asworth speaks on a temporary stage during the ongoing Extinction Rebellion climate change demonstration, near the Houses of Parliament in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Labour MP Jon Asworth speaks with an activist during the ongoing Extinction Rebellion climate change demonstration, near the Houses of Parliament in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Labour MP Jon Asworth speaks on a temporary stage during the ongoing Extinction Rebellion climate change demonstration, near the Houses of Parliament in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Climate change activists in red costume protest during the ongoing Extinction Rebellion climate change demonstration, near the Houses of Parliament in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

A climate change activist (L) yawns as an anti-Briexit demonstrator sits wrapped in an EU flag during the ongoing Brexit and Extinction Rebellion climate change demonstrations, near the Houses of Parliament in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

Police officers stand on duty as activists holding letters addressed to their MPs approach the Houses of Parliament during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Climate change activists holding letters addressed to their MPs react as they attempt to approach the Houses of Parliament during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Climate change activists holding letters addressed to their MPs react as they attempt to approach the Houses of Parliament during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

Climate change activists holding letters addressed to their MPs react as they attempt to approach the Houses of Parliament during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

Climate change activists holding letters addressed to their MPs react as they attempt to approach the Houses of Parliament during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

Climate change activists holding letters addressed to their MPs react as they attempt to approach the Houses of Parliament during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

Police officers stand on duty outside the Houses of Parliament as a climate change activist demonstrates in the road during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Baroness Jennifer Jones (4L) escorts climate change activists bearing letters addressed to their respective MPs, asking them to take action on environmental issues, into the Houses of Parliament to deliver the letters, during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Baroness Jennifer Jones reacts after escorting climate change activists bearing letters addressed to their respective MPs, asking them to take action on environmental issues, into the Houses of Parliament to deliver the letters, during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Baroness Jennifer Jones escorts climate change activists bearing letters addressed to their respective MPs, asking them to take action on environmental issues, into the Houses of Parliament to deliver the letters, during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by ISABEL INFANTES / AFP)

Climate change activists holding letters addressed to their MPs react, before being escorted to deliver the letters by Baroness Jennifer Jones (unseen), into Houses of Parliament during the ongoing Extinction Rebellion climate change demonstration, in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

An anti-Brexit demonstrator carries an EU flag as she passes a group of British police officers during the ongoing Brexit and Extinction Rebellion climate change demonstrations, near the Houses of Parliament in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

An anti-Brexit demonstrator carries an EU flag as she passes a group of British police officers during the ongoing Brexit and Extinction Rebellion climate change demonstrations, near the Houses of Parliament in central London on April 23, 2019. (Photo by Isabel Infantes / AFP)

Extinction Rebellion protesters from Oxford Circus. Police have removed protesters from Oxford Street, Waterloo Bridge and Parliament Square, but some activists remain in the trees and at Marble Arch. The group said it would march to Parliament on Tuesday morning to deliver letters inviting MPs to a Citizens' Assembly on the climate and ecological crisis. ? Alex Lentati / Evening Standard / eyevine

Extinction Rebellion protesters from Oxford Circus. Police have removed protesters from Oxford Street, Waterloo Bridge and Parliament Square, but some activists remain in the trees and at Marble Arch. The group said it would march to Parliament on Tuesday morning to deliver letters inviting MPs to a Citizens' Assembly on the climate and ecological crisis. ? Alex Lentati / Evening Standard / eyevine

Extinction Rebellion protesters from Oxford Circus. Police have removed protesters from Oxford Street, Waterloo Bridge and Parliament Square, but some activists remain in the trees and at Marble Arch. The group said it would march to Parliament on Tuesday morning to deliver letters inviting MPs to a Citizens' Assembly on the climate and ecological crisis. ? Alex Lentati / Evening Standard / eyevine

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Security forces stand guard as environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

LONDON, UNITED KINGDOM - APRIL 23: Security forces stand guard as environmental campaign group Extinction Rebellion (XR) march from their designated encampment place Marble Arch to Parliament Square in London, United Kingdom on April 23, 2019. British police took extensive security measures around Houses of Parliament and warned the group to evacuate Parliament Square before midnight. Tayfun Salci / Anadolu Agency/ABACAPRESS.COM

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Members of Extinction Rebellion who are campaigning for Government to legislate on Climate change, march from Marble Arch to Parliament Square. Extinction rebellion March. LONDON. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

Image ?Licensed to i-Images Picture Agency. 23/04/2019. London, United Kingdom. Four members of Extincyion Rebellion have climbed trees in Parliament Square and put up hammocks. The police have today announced that they will not be sending up food or water to the protestors. Extinction Rebellion tree dwellers. Parliament Square. Picture by Mark Thomas / i-Images

TOPSHOT - Graffiti left by climate change activists is seen as traffic and pedestrians move freely over Waterloo Bridge in London on April 22, 2019, after police cleared the protest camp after seven days of blockade by the Extinction Rebellion group. - Climate change protesters who have brought parts of London to a standstill said they were prepared to call a halt if the British government will discuss their demands. Some 831 arrests have been made and 42 people charged in connection with the ongoing Extinction Rebellion protests. On the seventh day of demonstrations that have occupied key spots in the British capital, organisers said they were willing to switch tactics from disruption to dialogue. The group's occupation of the Marble Arch site went into an eighth day on April 22. (Photo by Tolga Akmen / AFP)

TOPSHOT - Climate change activists are seen among tents at the Extinction Rebellion group's environmental protest camp at Marble Arch in London on April 22, 2019, on the eighth day of the group's protest calling for political change to combat climate change. - Climate change protesters who have brought parts of London to a standstill said Sunday they were prepared to call a halt if the British government will discuss their demands. Some 963 arrests have been made and 42 people charged in connection with the ongoing Extinction Rebellion protests. (Photo by Tolga Akmen / AFP)