Jeremy Corbyn says talks with the government to find a compromise over Brexit “have gone as far as they can”.
In a letter to the PM, the Labour leader said the six weeks of cross-party discussions could not carry on due to “the increasing weakness and instability” of the government.
No 10 said progress had been made in some areas, but the talks had been “very challenging”.
The parties are now expected to discuss putting a number of options to MPs.
The prime minister has promised to set a timetable for leaving Downing Street following a Brexit vote next month.
Environment Secretary Michael Gove said MPs needed to “focus on making sure that we honour [the] mandate” of leaving the EU given by the 2016 referendum.
Theresa May will try once again to win the support of MPs in the week beginning 3 June, when the Commons votes for the first time on the EU Withdrawal Agreement Bill – the legislation needed to implement her deal with the EU.
Brexit had been due to take place on 29 March – but after MPs voted down the deal Mrs May had negotiated with the bloc three times, the EU gave the UK an extension until 31 October.
This prompted negotiations between the Tories and Labour to see if the parties could come to a Brexit agreement.
But, in a letter to the prime minister, Mr Corbyn said the move towards choosing a new leader for the Conservative Party meant “the position of the government has become ever more unstable and its authority eroded”, undermining confidence in the “government’s ability to deliver any
compromise agreement”.
He also said that “not infrequently, proposals by your negotiating team have been publicly contradicted by statements from other members of the cabinet”.
Mr Corbyn described the talks as “detailed” and “constructive”, but said “while there are some areas where compromise has been possible, we have been unable to bridge important policy gaps between us”.
