The veteran Labour backbencher has tabled a motion of no confidence in Jeremy Corbyn as party leader after he failed to convince voters to back Remain.
The motion has no formal status but is expected to form the the basis of a discussion in the Parliamentary Labour Party.
Mr Corbyn faces a barrage of criticism from pro-EU Labour MPs, with former shadow minister Angela Smith accusing him of lacking commitment to the campaign.
She said: “Jeremy Corbyn needs to bear his share of the responsibility for the way in which he led the EU referendum campaign from a Labour perspective.
“He really ought to consider his position.
“If you are helping to lead the campaign for continued membership of the European Union then it’s clearly not acceptable to say you only support the EU on a scale of seven out of 10.
“We are looking for commitment over the future of the UK’s place in Europe.”
He does need to consider his position and think about whether he should do the honourable thing. Chris Leslie
Former shadow chancellor Chris Leslie said: “I would say today he does need to consider his position and think about whether he should do the honourable thing.”
Former Labour minister and EU commissioner Lord Mandelson said the referendum campaign showed Mr Corbyn “can’t cut it” as Labour leader.
The party faces bitter infighting after the EU referendum result. The overwhelming majority of Labour MPs backed Remain.
It is now incumbent to all party leaders to also reflect to what extent they are representing and reflecting the views of the voters. Gisela Stuart
Vote Leave chairman and Labour MP Gisela Stuart said: “It is now incumbent to all party leaders to also reflect to what extent they are representing and reflecting the views of the voters.”
Frontbencher Chris Bryant blamed former leader Ed Miliband, whose overhaul of the party’s rule book was widely seen to have paved the way for Jeremy Corbyn’s election as leader.
“I might go and punch him because he’s a tosspot and he left the party in the state it’s in,” Mr Bryant is reported to have said of Mr Miliband earlier in the week.
A senior Labour source said the mood within the party was one of “utter devastation, despair, horror”.