Jeremy Corbyn slams new Brexit deal as "worse than Theresa May's" as Labour refuse to back it.
It is a blow to the Prime Minister who faces a fight to get the last minute deal through the Commons after the DUP ruled out backing the deal.
Theresa May lost by 344 votes to 286 in the third so-called "meaningful vote" back in March, a margin of 58.
Asked at a press conference in Brussels over concerns UK MPs would derail the process, the EU's negotiator Michel Barnier said: "It's true that we have some experience in this matter."
He added: "the House of Commons will have to take that decision as is their responsibility"
But the Prime Minister insisted that he had the numbers during a phone call with EU Commission President Jean-Claude Juncker this morning.
He will hope that promises on workers' rights and environmental commitments are enough to convince the significant number of Labour MPs in Leave seats to vote for it.
Ruth Smeeth, who represents Stoke-on-Trent North, told ITV: "I want to vote for a deal and it is my intention to vote for a deal, unless Boris has completely undermined workers' rights, environmental rights and consumer rights."
Members of the cross-party group MPs for a Deal are understood to be considering their position.
Mr Corbyn, who is in Brussels for a meeting of the Party of European Socialists, hit out at the proposals on Northern Ireland.
He said: "This is a day where the Prime Minister seems to have made a deal with the European Union which doesn't give us the complete freedom of movement between Britain and Ireland because it creates a customs union border down the Irish Sea.
"As it stands we cannot support this deal.
"Also it is unclear whether it has the support of his allies in the DUP, or indeed many of his allies on his own backbenches."
"From what we know, it seems the Prime Minister has negotiated an even worse deal than Theresa May's, which was overwhelmingly rejected."
He added: “These proposals risk triggering a race to the bottom on rights and protections: putting food safety at risk, cutting environmental standards and workers’ rights, and opening up our NHS to a takeover by US private corporations.
“This sell out deal won’t bring the country together and should be rejected.
"The best way to get Brexit sorted is to give the people the final say in a public vote.”
But it is unclear whether the Labour Party will be whipping to support a plan to tack on a confirmatory referendum to the deal.
Mr Corbyn said he does not "suspect" Saturday will present a chance to get a confirmatory referendum through Parliament.
Asked if he would back a second referendum on Saturday when speaking in Brussels, he told reporters: "It won't come up on Saturday, I suspect."
