But the Prime Minister is braced for tough questioning by ministers at tomorrow’s weekly Cabinet meeting after the incendiary report that she has privately secured concessions from the European Union.
The UK wants agreement on its exit deal plus a “political declaration” on its future economic partnership with the EU to be concluded by the end of this month.
Rapid progress is needed to give the UK and EU countries time to ratify a deal in time for Britain to leave the bloc on March 29.
The Sunday Times said the EU was ready to let the whole UK stay in the customs union to avoid needing a “hard border” between Northern Ireland and Ireland.
Theresa May has always rejected the EU’s original plan for just Northern Ireland, and not the rest of the UK, to stay in the customs union in a “backstop” arrangement until a permanent border solution is found.
Ministers and Brexiteer MPs want any continuing customs union membership deal to include an end date, or a way that Britain can pull out of it.
Brexit Secretary Dominic Raab is reportedly telling colleagues that the future partnership statement will pave the way for a looser Canada-style free trade pact with the EU.
But one source said that was “false optimism” and customs union could effectively become the future UK-EU partnership – fatally limiting Britain’s ability to make new deals around the world.
Pro-Brexit Tory MP Kemi Badenoch told Sky News an “indefinite” UK-wide customs union deal would not be acceptable – and she would rather avoid even a time-limited one.
She added: “The PM has repeatedly said that we’d be leaving the customs union so whatever sort of deal we get it should be something that allows us to be trading more globally with the rest of the world and that’s the outlook that we want.”
Theresa May makes SECRET DEAL with EU to keep UK in customs union after Brexit
Amid speculation of an imminent deal, Government representatives insisted talks are ongoing with the EU – and also that Britain will be leaving the customs union.
A Downing Street source said: “We are not staying in the customs union.
“The Prime Minister could not have been clearer.
“We are making good progress on the future relationship and 95 per cent of the Withdrawal Agreement is now settled.
“Negotiations are ongoing.”
Communities and Local Government Secretary James Brokenshire told BBC One’s Andrew Marr: “We want to get that deal. We’ve working hard to see that that happens.
“Negotiations are still very firmly continuing.”
He added that the issue of “insurance” to ensure the Northern Ireland-Irish border remained free flowing “remains very much our focus”.
Germany’s ambassador to the UK, Peter Wittig, told Mr Marr: “There is a political will to come to a negotiated settlement and forge a new relationship, which is to be as close as possible with Britain, and Germany has a vital interest in coming to an agreement.”
But he also made clear his country and its businesses would not back a deal that threatened the integrity of the EU’s single market for trade.
Downing Street also insisted there would be no second EU referendum.
More than 70 serving and former business leaders signed an open letter calling for “a People’s Vote”, and Labour former PM Tony Blair urged MPs to vote down any deal Mrs May gets with Brussels and “give the people the final say”.
Further pressure came today after 1,400 of the UK’s top lawyers wrote to Mrs May saying people deserve another vote once the outcome of negotiations is known – which it was not in 2016.
A Downing Street source insisted yesterday: “The Prime Minister could not have been clearer: there will be no second referendum.
“We had a people’s vote in June, 2016 and we are focused on delivering on the results of that referendum. A second referendum would not be a people’s vote, it would be a politician’s vote.”
A Department for Exiting the EU spokeswoman said: “The people of the United Kingdom have already had their say in one of the biggest democratic exercises this country has ever seen and the Prime Minister has made it clear that there is not going to be a second referendum.
“We remain confident we will agree a mutually advantageous deal with the EU.”
A new survey has found support for having a new EU referendum if a deal was done with Brussels – but backing varies depending on the questions people would be asked.
Of 20,000 people interviewed online by Survation, 43 percent would back, and 37 percent would oppose, having a vote in which the choice was between accepting the deal or staying in the EU.
A smaller 38 percent would back having a choice between accepting the deal or leaving without one, and 39 percent would support being asked to accept the deal or reopen talks to get a better one.
The survey was for tonight’s Brexit: What the National Really Thinks programme on Channel 4.