UK Prime Minister Boris Johnson added his formal signature of the Brexit trade deal with the European Union (EU) on Wednesday soon after members of Parliament voted overwhelmingly for it, 521 votes to 73 in the House of Commons.

“The treaty that I’ve just signed is not the end, it is a new beginning and I think the beginning of what will be a wonderful relationship between the UK and our friends and partners in the EU,” Johnson said.

The documents had been flown to London in a Royal Air Force (RAF) plane after being signed by European Council President Charles Michel and European Commission President Ursula von der Leyen in Brussels on Wednesday morning.

Earlier, the UK PM had recalled Parliament from its Christmas break on Wednesday to get the Brexit free trade agreement (FTA) struck with the EU cleared through all parliamentary stages for the EU (Future Relationship) Bill to become law in time for January 1, 2021.

Also read: UK-EU post-Brexit deal: Effect on goods exports may be neutral

The 80-page Bill, which follows a last-minute deal agreed with the EU last week just days before the December 31 deadline of the end of the Brexit transition period, was debated by MPs in the Commons followed by the House of Lords. Johnson had urged MPs to back the “historic” Bill, which he said is not “a rupture but a resolution” of the UK’s relationship with its European neighbours and will allow Britain to take control of its “national destiny”.

Once both Houses pass the Bill, it will go immediately to the Queen for her Royal Assent for it to become law.

“What we sought was not a rupture but a resolution, a resolution of the old and vexed question of Britain’s political relations with Europe, which bedevilled our post-War history,” said Johnson, as part of his opening speech in the Commons.

“First we stood aloof, then we became a half-hearted, sometimes obstructive member of the EU. Now, with this Bill, we shall be a friendly neighbour – the best friend and ally the EU could have – working hand-in-glove whenever our values and interests coincide while fulfilling the sovereign wish of the British people to live under their own laws, made by their own elected Parliament. That is the historic resolution delivered by this Bill,” he said.

Once the Bill clears all the stages in record time, the UK-EU trade agreement will come into effect after 2300 GMT on Thursday. The once-rebellious Brexiteer wing of the Conservative Party fell behind the agreement, paving the way for a relatively smooth passage.

The Opposition Labour Leader, Sir Keir Starmer, had instructed his MPs to vote in favour of the deal, arguing the alternative would be a no-deal Brexit. He said the agreement would “put in place a floor from which we can build a strong future relationship with the EU”.

However, the Labour leader criticised the “thin deal” as having “many flaws” and said there was a “gaping hole” in the agreement’s provisions for the services sector.

Also read: What now for British economy with EU trade deal reached?

Northern Irish Democratic Unionist Party (DUP), which support Brexit in principle, voted against the trade deal due to concerns Northern Ireland remains tied to the EU more closely than the rest of the UK. The Scottish National Party (SNP) and Liberal Democrats had also voted against the legislation.

However, with Johnson’s comfortable majority in the Commons, the Bill was expected to clear the required parliamentary threshold to become law. It marks the culmination of four and a half long years of negotiations after the UK voted to leave the EU in June 2016.