Former London mayor Ken Livingstone said the election mauling for Labour spells "the end" for Jeremy Corbyn - before appearing to blame "the Jewish vote" for contributing to the losses.
The controversial ex-Labour, said his friend and ally Corbyn had paid the price for several aspects of his campaign, including not taking more action against anti-Semitism, reports the Mirror.
"The Jewish vote wasn't very helpful," Mr Livingstone said. "Jeremy should have tackled that issue far earlier than he did.
"It looks like the end for Jeremy, which is disappointing for me since I'm a close ally. I'm sure he'll have to resign tomorrow.
While Mr Corbyn was criticised for Labour's radical election platform, Mr Livingstone said he would have preferred the party to have been even bolder.
"I thought that perhaps they weren't radical enough," he said. "But at the end of the day, the public didn't like it. I think the idea for a four-day working week wasn't very popular at all."
It came during a brutal night for Labour, with Boris Johnson projected to win a majority of more than 80 seats and Corbyn announcing he would not lead Labour into another election.
Shadow Brexit Minister Jenny Chapman has lost her Darlington seat by more than 3,000 votes to the Tories.
The Tory candidate triumphed with 20,901 votes to Ms Chapman’s 17.607 - overturning her previous majority of 3,280.
The north east seat had been Labour since the 1990s but was predicted to go to the Tories along with nearly 30 others in a YouGov poll.
And Labour lost Workington - the seat identified by a think tank as a bellweather for the General Election .
