St Helens MP Conor McGinn says he is “distraught” about Labour’s plight and said the party’s electoral position is worse than the British troops in the Michael Caine film, Zulu.
Mr McGinn, who represents St Helens North and is a whip for the Labour Party, said: “I am distraught, like so many others, about what we are going through.”
Mr Corbyn has urged the party to unite, but Mr McGinn stressed: “Unity doesn’t mean that we get battered or ignored.”
And he joked that Labour was in a “much worse position” than the British troops in his favourite film Zulu.
He joined a number of other defiant Labour moderates who vowed to stay and fight following Mr Corbyn’s leadership victory amid warnings that the party’s future existence is at risk.
A series of senior MPs, including former shadow cabinet ministers Hilary Benn, Angela Eagle and Yvette Cooper took part in a rally hosted by the Labour First movement.
The packed rally heard repeated calls for people to remain in the party rather than quit in protest at Mr Corbyn’s re-election.
Former shadow cabinet minister Vernon Coaker set out the stark choice facing Labour, warning it could “die” unless it changed.
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.”
That did not mean “abandoning” what Labour stands for “but it does mean making it relevant to people in 2016 not 1976, making it relevant to people in 2020 not 1980”.
Mr Benn, who was sacked as shadow foreign secretary by Mr Corbyn, told the gathering: “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.”
He acknowledged that the atmosphere within Labour was “pretty unpleasant” and critics of the leader had been subjected to “vile abuse”.
But Labour MP Ruth Smeeth, who has been targeted with death threats, said: “If I’m not going anywhere, not one of you gets to go anywhere because we are staying and we are fighting.”
Former shadow cabinet minister Michael Dugher hit out at the hard left “screaming at the delegates” on their way into the Labour conference.
He 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.
“Don’t let anyone on the hard left of British politics and the hard left of our movement drive you out of what is still our party.”
He mocked Mr Corbyn over the “traingate” row with Virgin Trains. The rally, in a packed pub on the fringes of the Liverpool conference, spilled out into the street outside.
Mr Dugher said: “There is not a seat to be had. It reminds me of a certain train ride.”
Former shadow home secretary Ms Cooper urged Mr Corbyn to take action against the abuse directed at senior figures by a “minority” in the party.
She said: “I have congratulated Jeremy on his result but I have also called on him to keep us a broad-based party.
“That means that we have to do something about the minority of abuse that could end up driving good people out of this party.
“We are the party that has, throughout our history, campaigned against intimidation, against bullying, against oppression, be it by the powerful or be it by the mob.
“We must do so again, but how can we stand up for those values about common humanity if we don’t also use those values in treating each other and treating everyone within our party?”
Ms Eagle, who challenged Mr Corbyn for the leadership after the revolt within the party’s ranks at Parliament, was given a standing ovation.
She said: “We have all been subject to massive amounts of disgraceful and disgusting vile abuse.”
Ms Eagle said that she received 47,000 pieces of abuse after the simple act of changing her Facebook photo.
“They are trying to drive people out of the social media space, they are trying to drive people out of the public square, they are trying to drive people out of the party.
“The only way that we can deal with this is by standing up to it and the only way we can stand up to it is together. We have got to fight for decency in our party together.”
Former frontbench MP Angela Smith insisted the hard-left could be defeated.
She said: “We are going to win this. We have been here before, we were here in the 1980s.
“We will win our party back and we will make our party credible again on the economy, on international issues, on international security and particularly on Brexit.”
Labour moderates later packed out a rally of the Progress movement, where they heard more calls for centrists to stay in the party and fight.
Wirral South MP Alson McGovern was cheered as she brandished a Militant newsletter she said she had been handed on the way into the conference.
Merseyside-born McGovern told there delegates - who booed the mention of Militant: “These people helped bring this great city to its knees. These people ruined my childhood and I will not stand by as they ruin there next generation’s.”
Ms McGovern added: “These are challenging times indeed... There are people who are disillusioned and asking ‘What are we here for?’
“If anyone is thinking of leaving our party, I say this - if Liz Kendall can stay, Chuka Umunna.”