Theresa May (pictured arriving at Downing Street today) told Jeremy Corbyn his demand for Britain to stay in the EU's customs union would hamper free trade deals – but stopped short of ruling it out
Theresa May today moved to quell Tory fears she is about to cave into Jeremy Corbyn's demand for a permanent customs union with the EU.
Downing Street insisted the PM was 'absolutely clear' that she will not support the call from Labour.
'We must have our own independent trade policy,' her spokesman said.
The denial came after Mrs May caused panic in Tory ranks by appearing to open the door to a grand bargain with Labour.
Boris Johnson waded into the row this morning by warning that a customs union would 'frustrate' Brexit.
In a small piece of solace for Mrs May, he suggested he could vote for her deal if she manages to persuade the EU to put a time limit on the Irish backstop.
But the former foreign secretary insisted a legal 'codicil' - an amendment which would run alongside the Withdrawal Agreement - would not be enough to win him over.
Mrs May sparked the furore by penning a letter to Mr Corbyn saying his call for the UK to stay in a customs union would hamper free trade deals – but stopped short of ruling it out.
Mrs May also said the Tories were 'prepared to commit' to new laws to protect workers' rights after Brexit – a key demand of Labour and the unions.
But the hints at a cross-party pact, which could frustrate opposition from hardline Tory Eurosceptics, risked causing a Cabinet meltdown - with several senior figures including Liz Truss and Liam Fox thought to be ready to quit.
Brussels has so far flatly dismissed pleas from Mrs May to reopen the divorce package that they painstakingly thrashed out over two years, despite it being humiliatingly rejected by MPs last month.
Mrs May is now due to make a statement updating MPs on her progress renegotiating tomorrow, before the latest round of crunch votes are held on Thursday.
Boris Johnson (pictured giving a speech in Dublin last month) insisted staying in a customs union permanently would mean the UKJ being 'essentially a colony'
In her letter to Mr Corbyn (pictured on Saturday), May also confirmed that ministers are 'examining opportunities' to pour millions into deprived Brexit-voting Labour constituencies
Interviewed on BBC Radio 4's Today programme this morning, Mr Johnson insisted staying in a customs union permanently would mean the UK being 'essentially a colony'.
'It's clear that Jeremy Corbyn... he's done a complete U-turn,' he said.
'He now wants to frustrate Brexit very largely by staying in a permanent customs union.'
Mr Johnson indicated he would be willing to accept a time limit on the backstop as his price for backing Theresa May's EU Withdrawal Agreement.
'The argument is now about how to get out of the backstop. And how to make sure that the UK isn't locked in that prison of the customs union,' he said.
Up to 60 Labour MPs are 'actively looking for ways' to support the PM's Brexit deal, it was claimed today.
Wigan MP Lisa Nandy said she would not support Theresa May's plans in their current form.
But she said many of her colleagues were keen to get a package agreed.
The comments came as Mrs May confirmed she is ready to give commitments on the environment and workers' rights as she woos Opposition backing.
There have also been claims the government is looking to pump money into Brexit-voting areas to secure votes.
Ms Nandy told the BBC's Politics Live 40-60 Labour MPs were 'actively looking for ways to support this at the moment'.
'I think that you would need to have a time limit.'
But asked if changes to the backstop proposals could come in a separate codicil to the Withdrawal Agreement, Mr Johnson said: 'I don't think that would be good enough.'
In her letter to Mr Corbyn, Mrs May confirmed that ministers are 'examining opportunities' to pour millions into deprived Brexit-voting Labour constituencies. The move is seen as vital in winning the votes of Labour MPs for her deal.
The Prime Minister also proposed further talks with the Labour leader and his team in the coming days to discuss issues around the customs union, the single market and 'alternative arrangements' to the Irish backstop.
Her letter came hours after she was warned she could face a Cabinet walkout if she changes tack to pursue a customs union.
Treasury Chief Secretary Liz Truss yesterday refused three times to say whether she would remain in the Cabinet if a customs union became official policy.
Asked whether she would resign, she told Sky News: 'I absolutely do not think that should be our policy.'
Fellow Cabinet ministers Liam Fox, Andrea Leadsom and Penny Mordaunt are also said to be implacably opposed to any shift towards a customs union.
Dr Fox warned today that Labour proposals for a customs union with the EU are 'not workable'.
Liam Fox (pictured signing a trade deal in Switzerland today) has warned that Labour proposals for a customs union with the EU are 'not workable'
'Of course we always want to work with the opposition but the opposition has put forward some ideas that are not workable,' he told reporters in Bern at the signing of a new trade deal with Switzerland.
'The idea that you can have a customs union with the EU and at the same time, as an outside country, have an effect on EU trade policy is to not understand the EU treaties.
'It is very clear from the European Union that non-EU members do not have a say in EU trade policy so to pretend that you could do so is a dangerous delusion.'
Prisons minister Rory Stewart fueled talk of a Brexit compromise with Labour today.
The Remainer MP said both he and Theresa May believed it was possible to find common ground with the Opposition.
But he stress that it would not involve a customs union with the EU - despite that being Jeremy Corbyn's key demand.
'I think she feels, as I do, that there isn't actually as much dividing us from the Labour Party as some people suggest,' Mr Stewart told the BBC.
He denied there was any 'shifting of red lines', pointing out that the PM has repeatedly ruled out a customs union.
Prisons minister Rory Stewart fueled talk of a compromise with Labour today, saying: 'I think she feels, as I do, that there isn't actually as much dividing us from the Labour Party as some people suggest.'
But he denied there was any 'shifting of red lines', pointing out that the PM has repeatedly ruled out a customs union.
Many Brexiteers believe Mrs May is merely paying lip service to the idea of a pact with Mr Corbyn to frighten them into backing her deal.
Pressure is mounting on Mrs May as she faces revolts from both wings of the Conservative Party, with less than seven weeks to go until the UK is due to leave the EU.
Amid the deadlock, the premier is desperately playing for time to get more concessions from Brussels on the Irish backstop.
Labour is trying to use the latest round of crunch Commons votes on Thursday to force a decisive showdown on Mrs May's deal by the end of the month, whether or not she has managed to overhaul it.
However, Cabinet minister James Brokenshire suggested yesterday that Mrs May will try to delay the so-called 'meaningful vote' until next month.
Instead No10 is promising another round of indicative votes by February 27, hoping that will be enough to persuade wavering Tory Remainers that they can hold off staging an all-out rebellion against no-deal Brexit.
There is growing suspicion that Mrs May's tactic is to get as close as possible to March 29 before staging the vote, giving MPs a stark choice between the package she has thrashed out or crashing out without a deal.
Brexit Secretary Steve Barclay is preparing to fly to Strasbourg later to reopen talks with the EU's chief negotiator, Michel Barnier, for the first time since Mrs May's Commons defeat last month.
Ex-Brexit Secretary David Davis was spotted leaving Downing Street after a meeting today
Treasury Chief Secretary Liz Truss (file picture) yesterday refused to answer whether she would resign in the Cabinet if a customs union became official policy
The EU has flatly