European ambassadors will begin the process of approving the post-Brexit trade deal, as Britons were urged to prepare for life without the EUâ€™s benefits.
The diplomats will meet on Monday to determine how they can provisionally approve the deal covering Â£660 billion of trade in time for the end of the transition period on Thursday.
Tory Eurosceptics were urgently poring over the details of the treaty brokered on Christmas Eve ahead of MPs being recalled to vote on the deal on Wednesday.
Cabinet Minister Michael Gove was urging UK citizens to take out comprehensive travel insurance to cover health costs and check their mobile roaming policies to avoid charges if they are travelling to the EU.
He also warned businesses that the time is â€œvery shortâ€ to make the final preparations before the UK begins trading with its biggest trading partner and minimise what he said would amount to â€œsome disruptionâ€.
â€œIn just three daysâ€™ time the Brexit transition period will end and we will have finally regained our independence,â€ he added.
Conservative grandee Lord Heseltine urged MPs and peers to abstain when voting on Prime Minister Boris Johnsonâ€™s trade deal, warning it will inflict â€œlasting damageâ€ on the UK.
The former deputy prime minister said he will â€œin no way share the endorsement of the legislationâ€, but that he will not vote against it because the consequences of a no-deal would be even graver.
But it is likely to pass through both Houses, with Labour ordering its MPs to vote for the â€œthinâ€ treaty because the only other option is a chaotic departure without a trade deal.
The IPPR think tank warned that the â€œweaker than expectedâ€ protections in the treaty leaves workersâ€™ rights and environmental protections at risk of erosion.
But the Prime Minister denied the UK would regress on workersâ€™ rights and environmental standards, two issues both sides have committed to uphold in the deal.
â€œAll thatâ€™s really saying is the UK wonâ€™t immediately send children up chimneys or pour raw sewage all over its beaches. Weâ€™re not going to regress, and youâ€™d expect that,â€ he told the Sunday Telegraph.
The Prime Minister did acknowledge that the treaty â€œperhaps does not go as far as we would likeâ€ over access to EU markets for financial services.
But he said that Chancellor Rishi Sunak is â€œdoing a big exerciseâ€ on business taxes and regulation alongside a â€œgreat Government effortâ€ for change in the new year.
Mr Sunak said the nation will be able to â€œdo things a bit differentlyâ€ now, referencing new opportunities for the financial sector, and said the deal should leave those anxious about the financial impact â€œenormously reassuredâ€.
â€œI actually think this deal can represent an enormously unifying moment for our country and bring people together after the divisions of the past few years,â€ he told broadcasters.
But the chief executive of the National Federation of Fishermenâ€™s Organisation (NFFO), Barrie Deas, accused Mr Johnson of having â€œbottled itâ€ on fishing quotas to secure only â€œa fraction of what the UK has a right to under international lawâ€.
Mr Deas said the Prime Minister had â€œsacrificedâ€ fishing to other priorities, with the subject proving to be an enduring sticking point during negotiations.
A hasty analysis of the treaty secured on Christmas Eve began in earnest when it was published in full on Boxing Day â€“ less than a week before its implementation.
The self-styled â€œstar chamberâ€ of lawyers led by veteran Eurosceptic MP Sir Bill Cash and assembled by the European Research Group of Tory Brexiteers was expected to reveal its verdict on Tuesday.
But there were indications Brexit hardliners were preparing to support the deal, despite being angered by the little time they have to debate it.
Ian Blackford, the SNPâ€™s leader in Westminster, said his party would vote against the â€œunforgivable act of economic vandalism and gross stupidityâ€ which he argued is a â€œvery bad deal for Scotlandâ€.
Meanwhile, International Trade Secretary Liz Truss said she expects to sign a continuity trade agreement with Turkey this week, a move that was not possible until the deal with the EU was struck because Ankara is in a customs union with the bloc.
On Monday EU ambassadors will â€œtake the decision to provisionally apply the EU-UK agreement by written procedureâ€ and begin the process of approving the deal when they meet in Brussels, one diplomat said.
Their provisional approval is expected in the coming days ahead of the European Parliamentâ€™s formal ratification in the new year.