Members of the European Parliament were set to formally approve the terms of the United Kingdom's exit from the European Union on Wednesday evening, ending almost 50 years of British membership and opening the door to lengthy negotiations as both sides now seek a trade deal.

The unusual parliamentary session was expected to culminate with the rubber-stamping of the UK's looming exit, which will come at 11 pm on Jan 31. Key parliamentary committees within the European Parliament had already given their blessing to the Withdrawal Agreement last week, making Wednesday's vote largely symbolic. It was also signed last week by Charles Michel, president of the European Council, and Ursula von der Leyen, president of the European Commission.

Dominic Raab, the UK's foreign secretary, said the vote was "an historic moment that will legally bring an end to our membership of the European Union, and delivers on the promise we made to the British people".

"It is the start of a new chapter for an independent, sovereign Britain, looking forward to a decade of renewal and opportunity," he said. "Whether we are reducing trade barriers between nations, tackling climate change, or improving lives around the world, our vision of a truly global Britain will be a force for good."

The Withdrawal Agreement details such things as the rights of EU nationals living in the UK, and those of British expats on the continent, as well as arrangements for preventing a hard border on the island of Ireland.

Guy Verhofstadt, the Parliament's Brexit coordinator, had earlier said the legislature would miss the UK's 73 MEPs among the Parliament's 751 members, and their "knowledge, energy and wit".

Europe's main farewell to the UK is scheduled for Friday, when the president of the European Parliament, the president of the European Council, and the president of the European Commission are expected to issue a joint statement.

After the UK leaves, there will be an 11-month transitional period, during which the nation and the bloc will negotiate a future trade deal.

That transitional period will end on Dec 31 and Prime Minister Boris Johnson has insisted it will not be extended.

During the transition, the UK will be bound by EU rules while playing no role in the bloc's decision-making. The UK, which joined the precursor of the EU at the start of 1973, will also remain in the single market and the customs union during the transitional period and be under the jurisdiction of the European Court of Justice.

David Sassoli, the president of the European Parliament, told CNN on Tuesday that the timetable for the two sides to reach a trade deal will be tight but insisted it was essential that the two sides now build a new partnership based on friendly cooperation and mutual interests.

The Guardian newspaper reported that trade talks will start in earnest on March 3 with the European side led by Michel Barnier and the British side led by Johnson's Europe adviser David Frost.

Johnson is slated to deliver a speech next week in which he will set out the UK's opening negotiating position. And the EU is planning to define its opening negotiating position at a meeting of ministers on Feb 25. The Financial Times says the European Commission could, however, publish its draft mandate for the future relationship negotiations as early as Monday.