From the shock Brexit referendum result to Wednesday’s EU summit where Britain will ask for a delay, here are the milestones on the UK’s rocky road out of the European Union after 46 years.
Britain votes to leave
In a referendum on June 23, 2016, Britons choose to end their membership of the 28-nation EU by a narrow 52 percent to 48 percent.
Conservative prime minister David Cameron, who called the referendum and led the remain campaign, resigns.
May becomes prime minister
Theresa May, the remain-backing interior minister, becomes prime minister on July 13.
On January 17, 2017, May sets out her Brexit strategy, saying Britain will leave Europe’s single market to allow it to control EU immigration.
“No deal for Britain is better than a bad deal,” she insists.
Exit process triggered
On March 13, 2017, Britain’s parliament approves a bill empowering May to trigger Article 50 of the EU’s Lisbon Treaty which lays out the process for leaving the union.
With a letter to EU President Donald Tusk formally announcing Britain’s intention to leave, the government starts a two-year timetable for withdrawal on March 29, 2019.
In a bid to strengthen her hand in Brexit negotiations, May calls a snap election for June 8, 2017.
Her gamble backfires, with her Conservatives losing their parliamentary majority. They are forced to strike a deal for support from Northern Ireland’s Democratic Unionist Party.
Top ministers quit
On July 6, 2018, May wins agreement from her warring cabinet to pursue “a UK-EU free trade area” and strong alignment with the EU after Brexit.
Two days later, eurosceptic Brexit minister David Davis quits, saying May is giving “too much away too easily”. Foreign minister Boris Johnson follows suit on July 9.
Draft deal agreed
In November, May’s office says negotiators have reached a draft divorce agreement with the EU, which her cabinet backs after hours of heated debate.
But four ministers, including new Brexit secretary Dominic Raab, resign.
EU leaders approve the accord within a few weeks. “This is the only deal possible,” says European Commission President Jean-Claude Juncker.
May faces a furious backlash from her own party.
On December 12, enough Conservative MPs are unhappy with May’s party leadership to trigger a confidence vote, but she wins by 200 to 117.
British MPs reject deal
Parliament finally votes on the withdrawal agreement on January 15, 2019.
With opposition parties and scores of Conservatives opposing it for various reasons, MPs vote by 432 to 202 against the deal — the worst defeat for a government in modern British political history.
The deal is defeated again in two subsequent votes on March 12 and March 29, although by narrowing majorities.
Government survives vote
Main opposition Labour leader Jeremy Corbyn calls a vote of no confidence in the government on January 16.
The government wins by 325 to 306 votes, as May’s Conservatives rally round. She pledges to work with opposition leaders to find a Brexit breakthrough.
At a summit in Brussels on March 21, the EU agrees to a short delay but says Britain must outline a new plan by April 12 or face a no-deal Brexit.
May’s resignation pledge
In a dramatic meeting with fellow Conservatives on March 27, May promises to resign if her main leadership rivals support her deal and help it over the line.
Johnson, the former foreign minister, backs her, as does arch-eurosceptic Jacob Rees-Mogg.
But parliament still rejects the deal on March 29, forcing her to request another delay at a specially-convened summit on Wednesday.