Andy Burnham is expected to ask MPs on Monday to support the government's pursuit of a closer relationship with the European Union, arguing that Britain must seek a better long-term deal.
The Prime Minister's planned Commons address will develop the argument he made at Labour's conference that Brexit has done more harm than good.
He is expected to call for support across political parties, linking improved relations with Europe to economic growth and cooperation on immigration.
Burnham has said he will set out options for Britain's long-term European relationship around the next UK-EU summit. He has left open the possibility that those options could include renewed membership.
Monday's appeal is aimed at building agreement around the direction of negotiations and the wider debate. It does not amount to an announcement that Britain has applied to rejoin the EU or that a new deal has already been secured.
