The European Parliament has set the seal on Britain's departure from the EU, voting overwhelmingly to back Boris Johnson's Brexit deal.
MEPs, sitting in Brussels, voted by 621 to 49 in favour of the Withdrawal Agreement, paving the way for Britain to leave on Friday with a deal in place.
There were in the parliament as the result was announced with MEPs linking hands to sing a final chorus of Auld Lang Syne.
In contrast, Brexit Party leader Nigel Farage was greeted by cheers and the waving of Union flags by his party's MEPs as he declared Britain was "never coming back".
Their triumphal display drew a rebuke from the chair.
For most MEPs, who have long wanted Britain to stay, it was a moment of deep regret.
Addressing the parliament, European Commission president Ursula von der Leyen said she was determined the EU and the UK should remain "good friends and good partners".
She quoted the poet George Eliot, saying: "Only in the agony of parting do we look into the depth of love."
She added: "We will always love you and we will never be far, long live Europe."
The parliament's Brexit co-ordinator Guy Verhofstadt said the departure of a country which had "twice given its blood to liberate Europe" was a "sad" moment.
He predicted, however, that the UK would eventually rejoin, with many British people deeply unhappy at the prospect of leaving.
"In the last couple of days I have received hundreds of mails from British citizens saying they desperately want to stay or return," he said.
"So this vote is not an adieu, this vote, in my opinion, is only an au revoir."
He poured scorn on claims by supporters of Brexit that it would mean Britain recovering its sovereignty.
"What is in fact threatening Britain's sovereignty most - the rules of our single market or the fact that tomorrow they may be planting Chinese 5G masts in the British islands?" he said.
However in his final speech to the parliament, Farage insisted there could be no turning back once Britain was out.
"This is it, the final chapter, the end of the road, a 47-year political experiment that the British frankly have never been very happy with," he said.
The Brexit Party leader said he hoped Britain's departure would start a debate across the rest of Europe about the EU's future.
"I'm hoping this begins the end of this project. It's a bad project, it isn't just undemocratic, it's anti-democratic."
The vote in Brussels follows the completion last week of the passage of the Withdrawal Agreement Bill through the British Parliament at Westminster.
The agreement settles the terms of Britain's departure, including future citizens' rights, the arrangements on the Northern Ireland border and the UK's divorce settlement.
It also allows for an 11-month transition period, during which the UK will continue to follow EU rules while talks take place on a free trade agreement.
Johnson has said he wants a comprehensive deal - covering all aspects of Britain's future relationship with the EU, including security - by the end of the year.
He has been adamant that he will not contemplate any extension of the transition period beyond the end of 2020.
However, senior EU figures have repeatedly warned that reaching such a wide-ranging agreement will not be possible within such a tight timetable.
