EU leaders have approved an agreement on the UK’s withdrawal and future relations – insisting it is the “best and only deal possible”.
After 20 months of negotiations, the 27 leaders gave the deal their blessing after less than an hour’s discussion.
They said the deal – which needs to be approved by the UK Parliament – paved the way for an “orderly withdrawal”.
Theresa May said the deal “delivered for the British people” and set the UK “on course for a prosperous future”.
Speaking in Brussels, she urged both Leave and Remain voters to unite behind the agreement, insisting the British public “do not want to spend any more time arguing about Brexit”.
The UK is scheduled to leave the EU on 29 March 2019.
The EU officially endorsed the terms of the UK’s withdrawal during a short meeting, bringing to an end negotiations which began in March 2017.
European Commission President Jean-Claude Juncker said anyone in Britain who thought the bloc might offer improved terms if MPs rejected the deal would be “disappointed”.
But European Council President Donald Tusk, who broke the news of the agreement on Twitter, said he would not speculate on what would happen in such a situation, saying: “I am not a fortune teller.”
The UK Parliament is expected to vote on the deal on 12 December, but its approval is far from guaranteed.
Labour, the Lib Dems, the SNP, the DUP and many Conservatives MPs are set to vote against.
Mrs May has appealed to the public to get behind the agreement – saying that although it involved compromises, it was a “good deal that unlocks a bright future for the UK”.
The agreement, she added, would not remove Gibraltar from the “UK family” – a reference to a last-minute wrangle with Spain over the territory.
There was no formal vote on Sunday, with the EU proceeding by consensus.
Mr Juncker said it was a “sad day” and no-one should be “raising champagne glasses” at the prospect of the UK leaving.
While it was not his place to tell MPs how to vote, he said they should bear in mind that “this is the best deal possible…this is the only deal possible”.
His message was echoed by Irish Prime Minister Leo Varadkar who said “any other deal really only exists in people’s imagination”.
But Lithuanian President Dalia Grybauskaite suggested there were a number of possible outcomes if the UK Parliament rejected the deal, including an extension of the negotiations, or another referendum.