Downing Street's chief Brexit negotiator David Frost has hailed the trade deal with Brussels as beginning a "moment of national renewal" that eliminates the role of the European Court of Justice in the UK.
Lord Frost, speaking publicly for the first time since the deal was sealed, said it was "one of the biggest and broadest agreements ever", that ensures the UK "sets its own laws again".
"The way we've achieved that is there's no more role for the European Court of Justice, there's no direct effects of EU law, there's no alignment of any kind, and we're out of the single market and out of the customs union just as the manifesto said we would be," he said.
"This should be the beginning of a moment of national renewal for us. All choices are in our hands as a country and it's now up to us to decide how we use them and how we go forward in the future."
It comes as scrutiny of the deal begins, following the publishing of the 1,246-page document on the morning of Boxing Day.
Prime Minister Boris Johnson acknowledged to Conservative MPs that "the devil is in the detail" but insisted it would stand up to inspection from the European Research Group (ERG) of Brexiteers, who will assemble a panel of lawyers to examine the full text ahead of a Commons vote, on Dec 30.
The EU's 27 member states indicated they will formally back the deal agreed by the UK with Brussels' officials within days.
It covers trade worth about £660 billion and means goods can be sold without tariffs or quotas in the EU market.
EU ambassadors were briefed on the contents of the deal by Michel Barnier, who led Brussels' negotiating team in the talks with the UK.
After a highly unusual meeting on Christmas Day - with at least one diplomat wearing a Santa hat and another in a festive jumper - they agreed to write to the European Parliament to say they intend to take a decision on the provisional application of the deal.
The timing of the Christmas Eve deal forced politicians and officials in the UK and Brussels to tear up their plans.
MPs and peers will be called back to Westminster on December 30 to vote on the deal, but MEPs are not expected to approve it until the new year, meaning it will have to apply provisionally until they give it the green light.
The agreement will almost certainly be passed by Parliament, with Labour supporting it, as the alternative would be a chaotic no-deal situation on January 1.
But Mr Johnson is keen to retain the support of the Eurosceptics on his benches who helped him reach No 10.
On Boxing Day, Conservative former Cabinet minister Theresa Villiers told BBC Breakfast: "I very much hope this treaty stands up to scrutiny and I hope to be able to support it.
"But I was elected on a manifesto which promised to get Brexit done so I need to read (the document) before I can work out whether this actually enables us to do that or whether it traps us in the regulatory orbit of the European Union."
Mr Johnson had earlier messaged Tory MPs on WhatsApp as he tried to get them all on side.
"I truly believe this is the right deal for the UK and the EU," he wrote, in a message seen by the PA news agency.
"We have delivered on every one of our manifesto commitments: control of money, borders, laws, fish and all the rest.
"But even more important, I believe we now have a basis for long-term friendship and partnership with the EU as sovereign equals."