Andy Burnham will tell MPs it would be a “dereliction of duty” not to seek a new deal with the EU.
In a Commons address on Monday, the Prime Minister is expected to reiterate his argument from the Labour Party conference that Brexit has done “more harm than good”.
He will call on all parties to support the Government’s approach in seeking a closer relationship with the EU, arguing such a move could help control immigration and boost growth.
A No 10 source said: “Andy understands why some politicians don’t want to face up to the reality that Brexit has not delivered what they once promised.
“But it is time for a different conversation about what our long-term relationship should be.
“Sticking with the status quo and not working relentlessly to secure a good deal that boosts growth would be a major dereliction of duty.”
At the Labour conference in Liverpool last month, Mr Burnham said he would set out the “options” for Britain’s long-term relationship with Europe around the time of a UK-EU summit planned for the end of the year.
He has suggested that those options could include rejoining the bloc.
