Brussels leaders have today told Theresa May she has until midnight on Sunday to come up with a workable Brexit deal or EU leaders will not be able to open trade talks at next week’s summit.
But speaking on LBC, Mr Umunna said Brits had not been able to vote on factors such as the multi-billion divorce bill, which meant funds could not be poured into the NHS.
The former shadow business secretary said: “It’s not a question of whether people were conned or lied to and some might argue that they were.
“It is a bit of a question of government incompetence but I just think now that we’ve actually got the hard facts as these talks progress, it’s just proving impossible to deliver.
“Take the divorce bill that was just talked about.
“Nobody talked about there being this big divorce bill during the referendum campaign but this is a big new fact we now know exists and, of course, it’s going to mean that that £350million extra per week cannot go into the NHS.”
The EU Commission has insisted briefings by a senior official that Jean-Claude Juncker is prepared to extend the fraught negotiating process into next week are “not correct”.
Addressing journalists at the bloc’s Berlaymont home a spokesman insisted that progress must be made “this week, in this building” or there would not be enough time to seal a deal.
On Monday, the Prime Minister jetted out to Brussels fully expecting to sign off on a draft agreement with the 27 EU leaders, only for it to be torpedoed by her DUP colleagues at the last minute.
Unionist leaders, who had not seen the document, were left furious at suggestions that it would grant Northern Ireland a special status to solve the tricky border issue.