Theresa May will make a formal request to EU leaders on Wednesday to delay Brexit by extending the article 50 negotiating deadline as her government acknowledged that Britain was in crisis over its departure from the EU.
Amid reports of sharp disagreements among ministers at Tuesday’s cabinet meeting, the prime minister’s spokesman declined to offer details about the request.
"The prime minister will be writing to Donald Tusk, the president of the European Council, before the European Council begins in relation to an extension," he said.
Mrs May abandoned plans to put her Brexit deal to a vote at Westminster ahead of Thursday's EU summit after Commons speaker John Bercow warned on Monday that he would not allow a third vote on the deal if it had not changed.
The prime minister endorsed solicitor general Robert Buckland’s assertion that Mr Bercow’s intervention left Britain in a serious political crisis.
“If you were to look back at the speech the prime minister gave, just before meaningful vote two, she said that if MPs did not support meaningful vote two we would be in a crisis. Events yesterday tell you that that situation has come to pass,” her spokesman said.
Ministers discussed Brexit for 90 minutes on Tuesday morning, and Brexiteers led by Commons leader Andrea Leadsom are understood to have lobbied strongly against seeking an extension longer than three months.
Mrs May did not make clear before the end of the meeting exactly what kind of extension she would request from the EU.
Discussions between the British government and the DUP continued on Tuesday, but DUP deputy leader Nigel Dodds sounded a cautious note about their progress. He said the negotiations were going well, but there were still big gaps between the two sides.
"We have always been very clear about the conditions under which we would back any withdrawal agreement," he told the BBC. "And that is about the treatment of Northern Ireland in terms of single market and customs union compared to the rest of the United Kingdom."
Labour leader Jeremy Corbyn met the Westminster leaders of other opposition parties in an attempt to agree a common position on Mrs May's Brexit deal.
However, the SNP's Ian Blackford, the Liberal Democrats' Vince Cable, Plaid Cymru's Liz Saville Roberts and the Greens' Caroline Lucas complained that the Labour leader was insufficiently enthusiastic about a second referendum.
“Labour must move to back a public vote, which includes the option to remain, before the window of opportunity closes,” they said.
“There is no such thing as a good Brexit – whether it is a Labour or Conservative version of it – jobs, public services and the environment will suffer.
“Remaining in the EU is the best deal on offer, and with time running out Labour must now deliver on their promises so that we can avoid a catastrophic Brexit.”
Mr Corbyn also met Conservative and Labour MPs who want Britain to remain in the EU’s single market and customs union.