Brexit talks between the UK Government and Labour have collapsed after six weeks.
The Labour leader Jeremy Corbyn has written to Theresa May saying the discussions have "gone as far as they can."
Talks had been focused on trying to find a compromise to get the withdrawal agreement through parliament.
Mr Corbyn said the talks had taken place "in good faith on both sides", but claimed "important policy gaps" remained.
In his letter, he said: "The increasing weakness and instability of your government means there cannot be confidence in securing whatever might be agreed between us.
"As you have been setting out your decision to stand down and Cabinet ministers are competing to succeed you, the position of the government has become ever more unstable and its authority eroded."
I have written to Theresa May to say that talks on finding a compromise agreement for leaving the European Union have gone as far as they can.
The government's growing weakness and instability means there cannot be confidence in its ability to deliver. pic.twitter.com/H27qxDleaB
— Jeremy Corbyn (@jeremycorbyn) May 17, 2019
It was hoped a deal could be reached before Mrs May sets out a timetable for her own departure next month.
Boris Johnson has already he said he wants the top job.
The British government is to make one more attempt to get the withdrawal deal through the House of Commons during the week beginning June 3rd.
Labour says they won't back it unless there are "significant changes".