Jeremy Corbyn has refused to resign as Labour leader despite the party's MPs overwhelmingly backing a vote of no confidence.
A total of 172 MPs said they had no confidence in Corbyn compared to 40 who backed him.
Corbyn has remained defiant, saying the ballot had "no constitutional legitimacy" and he would "not betray" the party members who elected him by resigning.
The result will likely trigger a leadership contest.
ITV News understands Angela Eagle is the most likely to challenge Corbyn for the leadership.
Tom Watson was also touted as a possible contender.
The party has been embroiled in a tense internal stand-off since the referendum vote with a string of shadow cabinet ministers resigning in protest at Corbyn.
A fraught party meeting was held on Monday where some MPs were reportedly left in tears as Mr Corbyn reiterated that he would not be standing down.