JEREMY Corbyn has said he has obtained a confidential report which "drives a coach and horses" through Boris Johnson's claim that there will be no border in the Irish Sea under his Brexit plan.
The Labour leader said the leaked document, marked "official, sensitive", provides the "cold, hard evidence" that the Prime Minister has been "misleading" people about his withdrawal deal.
Brandishing a document, titled Northern Ireland Protocol: Unfettered Access To The UK Internal Market, at a press conference in central London yesterday, Mr Corbyn said it was proof that there would be customs checks between Great Britain and Northern Ireland after Brexit.
Conservative leader Mr Johnson has repeatedly said there will be no border in the Irish Sea.
He dismissed Labour's claims as "complete nonsense".
Asked about the Labour leader's claims, Mr Johnson said: "I haven't seen the document you're referring to but that's complete nonsense, and what I can tell you is that with the deal that we have we can come out as one whole UK."
He later added: "They should believe exactly what I say, which is that there will be no goods going from GB to NI or from NI to GB because we are going to come out of the EU whole and entire, and that was the objective that we secured."
The Conservatives claim the document presented by Mr Corbyn was only an immediate assessment of the PM's deal and represents a "flash" and incomplete analysis which had not been seen by Mr Johnson.
Last month, the PM suggested Brexit Secretary Stephen Barclay had been wrong to say goods between Northern Ireland and the rest of the UK would face checks as a result of the deal struck with the EU.
Ulster Unionist leader, Steve Aiken said his party "warned of the catastrophe that Johnson's deal would be for Northern Ireland".
"We warned of the dangers posed by the original Withdrawal Agreement in December 2017," he said.
"That was the start of the slippery slope to where we are today, but the DUP didn't listen.
"The DUP claimed to have a unique position of influence within Westminster and held the balance of power for over two years. Regrettably that ‘influence’ has delivered a border in the Irish Sea.
"The DUP must now explain why they supported a regulatory border in the Irish Sea on October 2, which cleared the way for Boris Johnson to attempt to throw Northern Ireland overboard.
"The public deserve to know which DUP MPs were involved in negotiations with the government in the run up to Johnson`s deal and what they agreed?
"They should also reveal what additional financial package they were offered in return for their support for a regulatory border in the Irish Sea."
Sinn Féin's Paul Maskey said: "Since the referendum and the ideological crusade the Tories and the DUP have embarked on, we have consistently said there is no such thing as a good Brexit.
"Brexit is particularly damaging for business and the DUP have to explain to the business community whether they are supporting this reckless agenda."
The DUP's Jeffrey Donaldson however said the leaked document demonstrated that the deal is bad for Northern Ireland.
"The DUP warned the Prime Minister about this. Despite his protestations, the facts are in black and white. That is why we opposed the deal in the House of Commons and why Northern Ireland needs the deal changed.
"We have demonstrated over the last three years that we will stand up and speak up for Northern Ireland to ensure our economy is not decimated by a bad deal," said the Lagan Valley Westminster candidate.
"Jeremy Corbyn is using this as a campaigning tool but no unionist will be tricked by his rhetoric. He has in the past and would in the future work in cahoots with those who want to destroy the union."
