An anti-Brexit protestor straightens her wig outside the Houses of Parliament on January 15, 2019 in central London as Parliament prepares to finally vote on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

An anti-Brexit protestor straightens her wig outside the Houses of Parliament on January 15, 2019 in central London as Parliament prepares to finally vote on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Pro and anti-Brexit demonstrators start the day outside the Houses of Parliament on January 15, 2019 in central London as Parliament prepares to finally vote on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

An anti-Brexit demonstrator starts the day outside the Houses of Parliament on January 15, 2019 in central London as Parliament prepares to finally vote on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Anti-Brexit campaigners protest outside Parliament on January 15, 2019 in central London. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Anti-Brexit campaigners protest outside Parliament on January 15, 2019 in central London. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Anti-Brexit campaigners protest outside Parliament on January 15, 2019 in central London. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Pro and anti-Brexit campaigners protest outside Parliament on January 15, 2019 in central London. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Anti-Brexit campaigners protest outside Parliament on January 15, 2019 in central London. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Anti-Brexit campaigners protest outside Parliament on January 15, 2019 in central London. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Anti-Brexit campaigners protest outside Parliament on January 15, 2019 in central London. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

An anti-Brexit campaigner folds a flag outside Parliament on January 15, 2019 in central London. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

A man wears a luminous hat with an anti-Brexit slogan on it amid protesters outside Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

A man wears a luminous hat with an anti-Brexit slogan on it amid protesters outside Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

Anti-Brexit demonstrators hold up placards outside Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

Anti-Brexit supporters hold up placards outside Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

Anti-Brexit protesters with EU flags are seen outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

Anti-Brexit protesters with EU flags are seen outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

An anti-Brexit protester (L) holds a banner next to a pro-Brexit protester (R) outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

Anti-Brexit protesters shout with placards outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

An anti-Brexit protester uses a smartphone outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

A pro-Brexit 'battle bus' (L) drives past a mix of pro-Brexit and anti-Brexit protesters outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

An anti-Brexit 'battle bus' arives past protesters outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

Mostly anti-Brexit protesters wave EU and Union flags with one UK Independence Party flag (UKIP) (2R top) outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP)

Two anti-Brexit protesters are seen outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Oli SCARFF / AFP) / RESTRICTED TO EDITORIAL USE - MANDATORY MENTION OF THE ARTIST UPON PUBLICATION - TO ILLUSTRATE THE EVENT AS SPECIFIED IN THE CAPTION

An anti-Brexit protester is seen outside the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Daniel LEAL-OLIVAS / AFP)

An anti-Brexit bus with an offensive slogan printed on the side is driven past the Houses of Parliament in central London on January 15, 2019. - Parliament is to finally vote today on whether to support or vote against the agreement struck between Prime Minister Theresa May's government and the European Union. (Photo by Paul ELLIS / AFP)

Image ?Licensed to i-Images Picture Agency. 15/01/2019. London, United Kingdom. Brexit Vote Westminster. Anti-Brexit pro-EU protesters gather at Old Palace Yard opposite the Houses of Parliament. The People's Vote stunt was organised by campaign lobby group Avaaz. Today in Parliament a historic vote will take place as MPs decide whether or not to accept the Governments Brexit deal. Picture by Pete Maclaine / i-Images

Image ?Licensed to i-Images Picture Agency. 15/01/2019. London, United Kingdom. Brexit Vote Westminster. Anti-Brexit pro-EU protesters gather at Old Palace Yard opposite the Houses of Parliament. The People's Vote stunt was organised by campaign lobby group Avaaz. Today in Parliament a historic vote will take place as MPs decide whether or not to accept the Governments Brexit deal. Picture by Pete Maclaine / i-Images

Anti-Brexit supporters hold placards and flags as they demonstrate outside the Houses of Parliament on January 14, 2019. - Prime Minister Theresa May on Monday published further assurances from the EU on the eve of a crucial parliamentary vote on her Brexit deal and warned MPs that rejecting it would lead to "paralysis" that could see Britain stay in the bloc. (Photo by Oli SCARFF / AFP)

Anti-Brexit supporters hold placards and flags as they demonstrate outside the Houses of Parliament on January 14, 2019. - Prime Minister Theresa May on Monday published further assurances from the EU on the eve of a crucial parliamentary vote on her Brexit deal and warned MPs that rejecting it would lead to "paralysis" that could see Britain stay in the bloc. (Photo by Oli SCARFF / AFP)

Anti-Brexit supporters hold flags as they demonstrate outside the Houses of Parliament on January 14, 2019. - Prime Minister Theresa May on Monday published further assurances from the EU on the eve of a crucial parliamentary vote on her Brexit deal and warned MPs that rejecting it would lead to "paralysis" that could see Britain stay in the bloc. (Photo by Oli SCARFF / AFP)

Anti-Brexit supporters hold European Union flags as they demonstrate outside the Houses of Parliament on January 14, 2019. - Prime Minister Theresa May on Monday published further assurances from the EU on the eve of a crucial parliamentary vote on her Brexit deal and warned MPs that rejecting it would lead to "paralysis" that could see Britain stay in the bloc. (Photo by Oli SCARFF / AFP)

TOPSHOT - Anti-Brexit supporters hold placards and flags as they demonstrate outside the Houses of Parliament on January 14, 2019. - Prime Minister Theresa May on Monday published further assurances from the EU on the eve of a crucial parliamentary vote on her Brexit deal and warned MPs that rejecting it would lead to "paralysis" that could see Britain stay in the bloc. (Photo by Oli SCARFF / AFP)