Labour’s Tom Watson has called off talks with unions aimed at resolving the stand-off at the top of the party.
The deputy leader said Mr Corbyn’s declaration that he would continue as leader “come what may” meant there was “no realistic prospect of reaching a compromise” over his future.
He said there was now “little to be achieved” by holding talks with unions.
The Unite union had been due to meet representatives of Mr Corbyn and Labour MPs in Brighton on Sunday.
Mr Watson said he had made “significant progress” during initial talks with union representatives earlier this week.
He said it was his “strong belief” that these discussions could have led to a basis for further talks.
“However, since the talks began Jeremy has publicly declared his intention to continue as leader come what may,” he added.
MPs and senior Labour figures have called for Mr Corbyn to resign in the wake of the EU referendum and a motion of no confidence was passed by the party’s MPs last month.
But the leader’s office maintained earlier this week that “there will be no resignation”.