There will not be a finalised Brexit deal on Wednesday, BBC political editor Laura Kuenssberg reported, citing an unnamed UK government source.
"Government source has just told me there will not be a deal tonight," she said in a tweet, with European Union sources saying that Britain and the EU were on the verge of a deal.
She added: "Simply not clear if that means there's no way forward yet or just a case of extending talks into tomorrow (because) they need a bit more time."
The political editor of the Sun newspaper also said there would be no Brexit deal on Wednesday. He added that there were unresolved issues with both the EU and the Northern Irish Democratic Unionist Party (DUP) who support the Conservative minority government in Britain's parliament.
"Everyone will be working into the night but there won't be a deal this evening," Tom Newton-Dunn quoted a government source as saying.