AP PHOTOS: Britain's long, complicated divorce from Europe

FILE - In this Friday, June 24, 2016 file photo file photo a statue of Winston Churchill is silhouetted against the Houses of Parliament and the early

FILE - In this Friday, June 24, 2016 file photo file photo a statue of Winston Churchill is silhouetted against the Houses of Parliament and the early

FILE - In this Friday, June 24, 2016 file photo Nigel Farage, the leader of the UK Independence Party speaks to the media on College Green with the Ho

FILE - In this Friday, June 24, 2016 file photo Nigel Farage, the leader of the UK Independence Party speaks to the media on College Green with the Ho

FILE - In this Friday, June 24, 2016 file photo Nigel Farage, the leader of the UK Independence Party, celebrates and poses for photographers as he le

FILE - In this Friday, June 24, 2016 file photo Nigel Farage, the leader of the UK Independence Party, celebrates and poses for photographers as he le

FILE - In this Wednesday, July 13, 2016 file photo Britain's Prime Minister David Cameron, speaks to the media as his wife Samantha and their children

FILE - In this Wednesday, July 13, 2016 file photo Britain's Prime Minister David Cameron, speaks to the media as his wife Samantha and their children

FILE - In this Wednesday, July 13, 2016 file photo Britain's Prime Minister David Cameron, his wife Samantha and their children Nancy, Elwen and Flore

FILE - In this Wednesday, July 13, 2016 file photo Britain's Prime Minister David Cameron, his wife Samantha and their children Nancy, Elwen and Flore

FILE - In this Wednesday, July 13, 2016 file photo, new British Prime Minister Theresa May and her husband Philip May stand on the steps of 10 Downing

FILE - In this Wednesday, July 13, 2016 file photo, new British Prime Minister Theresa May and her husband Philip May stand on the steps of 10 Downing

FILE - In this Tuesday March 28, 2017 file photo, Britain's Prime Minister Theresa May, sitting below a painting of Britain's first Prime Minister Rob

FILE - In this Tuesday March 28, 2017 file photo, Britain's Prime Minister Theresa May, sitting below a painting of Britain's first Prime Minister Rob

FILE- In this Wednesday, March 29, 2017 file photo, EU Council President Donald Tusk holds British Prime Minister Theresa May's Brexit letter in notic

FILE- In this Wednesday, March 29, 2017 file photo, EU Council President Donald Tusk holds British Prime Minister Theresa May's Brexit letter in notic

FILE - In this Friday, Oct. 20, 2017 file photo, British Prime Minister Theresa May waits for the arrival of European Council President Donald Tusk pr

FILE - In this Friday, Oct. 20, 2017 file photo, British Prime Minister Theresa May waits for the arrival of European Council President Donald Tusk pr

FILE - In this Monday, March 19, 2018 file photo European Union chief Brexit negotiator Michel Barnier, right, gestures as he meets with British Secre

FILE - In this Monday, March 19, 2018 file photo European Union chief Brexit negotiator Michel Barnier, right, gestures as he meets with British Secre

FILE - In this Friday, Aug. 31, 2018 file photo Britain's Secretary of State for Exiting the European Union Dominic Raab, left, and EU chief Brexit ne

FILE - In this Friday, Aug. 31, 2018 file photo Britain's Secretary of State for Exiting the European Union Dominic Raab, left, and EU chief Brexit ne

FILE - In this file photo taken on Wednesday, Oct. 10, 2018, a sign in a parking lot of a cemetery reads: "No EU border in Ireland" near Carrickcarnan

FILE - In this file photo taken on Wednesday, Oct. 10, 2018, a sign in a parking lot of a cemetery reads: "No EU border in Ireland" near Carrickcarnan

FILE - In this Monday, Dec. 3, 2018 file photo protestors are reflected in a puddle as they wave European flags to demonstrate against Brexit in front

FILE - In this Monday, Dec. 3, 2018 file photo protestors are reflected in a puddle as they wave European flags to demonstrate against Brexit in front

FILE - In this Thursday, Nov. 15, 2018 file photo EU chief Brexit negotiator Michel Barnier, left, delivers the draft withdrawal agreement to European

FILE - In this Thursday, Nov. 15, 2018 file photo EU chief Brexit negotiator Michel Barnier, left, delivers the draft withdrawal agreement to European

FILE - In this Thursday, Dec. 13, 2018 file photo Britain's Ambassador to the EU Sir Tim Barrow, right, gestures to British Prime Minister Theresa May

FILE - In this Thursday, Dec. 13, 2018 file photo Britain's Ambassador to the EU Sir Tim Barrow, right, gestures to British Prime Minister Theresa May

FILE - In this Thursday, Feb. 7, 2019 file photo European Commission President Jean-Claude Juncker prepares to shake hands with British Prime Minister

FILE - In this Thursday, Feb. 7, 2019 file photo European Commission President Jean-Claude Juncker prepares to shake hands with British Prime Minister

FILE - In this Wednesday, Feb. 27, 2019 file photo the flag of the European Union and the British national flag are flown on poles during a demonstrat

FILE - In this Wednesday, Feb. 27, 2019 file photo the flag of the European Union and the British national flag are flown on poles during a demonstrat

FILE - In this Wednesday, Feb. 27, 2019 file photo a leave the European Union (EU) supporter, at right, holds a placard up in front of remain in the E

FILE - In this Wednesday, Feb. 27, 2019 file photo a leave the European Union (EU) supporter, at right, holds a placard up in front of remain in the E

FILE - In this Sunday, Feb. 24, 2019 file photo British Prime Minister Theresa May, center, listens as Luxembourg's Prime Minister Xavier Bettel, seco

FILE - In this Sunday, Feb. 24, 2019 file photo British Prime Minister Theresa May, center, listens as Luxembourg's Prime Minister Xavier Bettel, seco

FILE - In this Monday, March 4, 2019 file photo a carnival float depicts British Prime Minister Theresa May and the Brexit during the traditional carn

FILE - In this Monday, March 4, 2019 file photo a carnival float depicts British Prime Minister Theresa May and the Brexit during the traditional carn

FILE - In this Thursday, Feb. 14, 2019 file photo Remain in the European Union supporters wear blindfolds as they take part in a protest event organis

FILE - In this Thursday, Feb. 14, 2019 file photo Remain in the European Union supporters wear blindfolds as they take part in a protest event organis

FILE - In this Tuesday, March 12, 2019 file photo a Pro-Brexit leave the European Union supporter takes part in a protest outside the Houses of Parlia

FILE - In this Tuesday, March 12, 2019 file photo a Pro-Brexit leave the European Union supporter takes part in a protest outside the Houses of Parlia

FILE - In this Tuesday March 12, 2019 file photo Britain's Prime Minister Theresa May speaks to lawmakers in parliament, London. Britain's love-hate r

FILE - In this Tuesday March 12, 2019 file photo Britain's Prime Minister Theresa May speaks to lawmakers in parliament, London. Britain's love-hate r

FILE - In this Thursday March 14, 2019 file handout photo provided by UK Parliament, Britain's Prime Minister Theresa May, first row centre, laughs du

FILE - In this Thursday March 14, 2019 file handout photo provided by UK Parliament, Britain's Prime Minister Theresa May, first row centre, laughs du

LONDON (AP) — Britain's love-hate relationship with the rest of Europe goes back decades, but the Brexit crisis gripping it today stems from a dramatic January 2013 speech by Prime Minister David Cameron in which he promised an "in or out" referendum.

The vote would be to determine whether Britons wanted to stay in the European Union, or sever ties.

The actual referendum was held in June 2016, and Cameron — a youthful prime minister enjoying his second term in office — became its first casualty after he failed to convince voters that the benefits of EU membership outweighed the liabilities.

The vote was 52 percent to 48 in favor of leaving. A chagrined Cameron, with his wife by his side, walked out of 10 Downing Street the morning after and resigned.

Big winners, it seemed, were Boris Johnson and Nigel Farage, luminaries of the "Leave" campaign whose "take back control" arguments carried the day, bolstered by unsubstantiated claims that leaving the EU would allow Britain to add 350 million pounds ($455 million) a week to the National Health Service budget.

But it was Theresa May, Cameron's home secretary, who emerged as the Conservative Party choice as his successor and was charged with the task of leading Britain out of the EU — a task that has turned out to be more difficult than most anticipated.

She formally triggered Britain's departure plan in 2017 by sending the EU a letter invoking Article 50. A March 29, 2019, departure date was set.

So far, so good. But negotiations between Britain and the EU have been slow and at times acrimonious, and the 585-page withdrawal agreement produced after two years of talks has been rejected twice by Britain's divided Parliament.

That has led to Britain's decision to seek a delay in the deadline as May prepares, once again, to seek parliamentary backing. It is not clear what path she will take if she fails a third time.