British Prime Minister Theresa May's government on Thursday repeated its opposition to negotiating a future UK-EU customs union, after the opposition Labour Party named that as its price for backing her Brexit plan.
The rebuff came after an official in Brussels said EU President Donald Tusk had told May that the plan from main opposition Labour leader Jeremy Corbyn "might be a promising way out of the impasse".
Corbyn wrote to May ahead of her meetings with EU leaders in Brussels on Thursday, setting out his terms for supporting her withdrawal deal following its rejection by MPs last month.
He noted the EU has rebuffed her efforts to modify the controversial Irish "backstop" arrangement in the deal, but outlined changes to an accompanying political declaration on future ties that he said would secure his backing.
These include a commitment to a "permanent and comprehensive" UK-EU customs union, in which Britain has a "say" on future European Union trade deals.
May has repeatedly said that a customs union would stop Britain signing its own trade deals, and her Downing Street office repeated this on Thursday.
"It's welcome that the leader of the opposition is engaging in this and it's important that we continue to hold discussions to find a way forward to deliver Brexit," an official said.
"We are looking at those proposals with interest but there are obviously very considerable points of difference that exist between us.”
In his letter, Corbyn also called for "close alignment" with the EU's single market, underpinned by shared institutions and obligations.