Video report by ITV News deputy political editor Chris Ship
A series of senior Labour MPs, including former shadow cabinet ministers who resigned under Jeremy Corbyn, have urged colleagues to remain in the party and fight to win back the party.
Hilary Benn, Angela Eagle and Yvette Cooper all took part in a rally hosted by the Labour First movement, held close to the Liverpool conference centre where Labour is holding its party conference.
Speaker after speaker called for people to remain in the party rather than quit in protest at Mr Corbyn's re-election.
Mr Benn, who was sacked as shadow foreign secretary by Mr Corbyn, told the crowd: "Don't be disheartened because in the end the values that bind us together will win.
"So for all of the difficulties and the problems that people may feel today, I say to you today be of good heart, be of good cheer, stick together and we will win."
For his part Mr Corbyn has called on MPs to "move on" from Labour's bitter leadership battle, saying on the BBC's Andrew Marr show that his party was "quite united" on policy.
That unity was less obvious at the rally, which appeared so popular that it spilled outside the venue into the street.
Vernon Coaker, a former shadow cabinet minister, warning Labour could "die" if the party did not change.
He said: "The real task, of course, is changing the membership and winning the party back to the views of electability as well as principle."
But he added: "The political terms of trade in this country are changing. The Labour Party has to change. Our policies have to change. If we don't change we will die."
Speakers at the event all appeared to agree that they would not abandon the party.
Former shadow cabinet minister Michael Dugher, said: "The Labour Party may be going nowhere with the public at the moment but let's send a message loud and clear from this room: We are going nowhere, the people in this room.
"This is our party and we stay and we fight."
Separately, at a fringe event at the conference, former party leader Ed Miliband insisted there is a need for Labour to unify behind Mr Corbyn's leadership to enable the opposition to take on a government which is "clueless" about Brexit.