After a disastrous vote in the House of Commons on her withdrawal agreement with the European Union, Theresa May presented her alternative Brexit plan to the members of Parliament on January 21.

May said that after hearing the concerns of Parliament, she is seeking to gain concessions from the EU on the controversial Northern Ireland “backstop,” or temporarily fluid border between EU-member Ireland and Northern Ireland, which is part of the United Kingdom. The backstop remains the most contentious issue of Brexit negotiations and faces opposition on all sides of Parliament.

The United Kingdom is scheduled to leave the European Union on March 29, 2019. UK Prime Minister Theresa May has been scrambling to draft and pass a withdrawal agreement that would prevent a costly and diplomatically destructive exit from the EU without a deal. At the conclusion of a five-day debate, the British legislative House of Commons rejected May’s deal and increased the likelihood of a “no-deal” Brexit. Here are the key dates and players that have led up to the January 15 vote by the members of Parliament.