Jeremy Corbyn has urged Labour MPs to unite behind him if, as expected, he is returned as party leader with an even bigger mandate from grassroots members.
The veteran left-winger is the overwhelming hot favourite to see off the challenge from rival Owen Smith when the results of the leadership election are announced in Liverpool shortly before midday.
He received support from senior shadow cabinet member Andy Burnham, who stayed neutral in the leadership contest. Mr Burnham said he would have earned the right to lead "without interruptions, noises off and undermining".
The shadow home secretary said Labour MPs had treated Mr Corbyn appallingly when he became leader last year and should now be prepared to serve on his frontbench and "do so in the right spirit".
"I've never seen in 15 years a Labour leader treated like that; it was disrespectful," he told The Guardian.
But Lisa Nandy, who quit the shadow cabinet following the referendum vote for Brexit in protest at Mr Corbyn's leadership style, warned there would have to be a change of culture if he was to reunite the party.
"A political party, a social movement, a shadow cabinet simply cannot survive if you refuse to hear dissenting voices and work as a team to try and resolve differences," she told BBC2's Newsnight. "Then it is not a shadow cabinet, it is quite simply just a fan club."
In a video message to supporters, Mr Corbyn insisted that internal critics had a "duty to unite", regardless of the margin of victory.
After private talks this week with senior MPs on Labour's moderate wing, Mr Corbyn is expected to seek to rebuild his frontbench team in the wake of the expected confirmation of his position.
The resignation of more than 40 frontbenchers in June left him unable to fill all his shadow ministerial posts and reports have suggested that as many as 14 may be ready to return following the apparent failure of Mr Smith's bid to unseat him.
But others, including Hilary Benn, Yvette Cooper and Chuka Umunna are thought likely to focus on their bids to secure the chairmanship of influential parliamentary committees, which will allow them to take prominent roles scrutinising Theresa May's government from outside Mr Corbyn's camp.
Labour's ruling National Executive Committee is due to meet after the result is announced, having put off a decision earlier this week on proposals to restore elections to the shadow cabinet, which might have given some centrist MPs a route back into Mr Corbyn's top team.
It was not clear whether the issue will be settled over the course of the coming week's annual conference in Liverpool, with Mr Corbyn preferring a wider review of Labour's democratic structures to give more decision-making power to the membership.
In his video message, Mr Corbyn said: "This isn't and never has been about me. It's about all of us. Whatever the result, whatever the margin, we all have a duty to unite, cherish and build our movement."
Rejecting the claims of critics that he is more interested in consolidating the left's hold over Labour than in winning power, Mr Corbyn insisted that the wave of enthusiasm which drove his second leadership campaign - just a year after he was first elected - would boost the party's hopes in the general election scheduled for 2020.
With 40,000 volunteers signing up to take part in his leadership campaign and membership numbers swelling to more than half a million, Mr Corbyn said Labour would be able to deliver "a new kind of general election campaign - the biggest, best and most visible we have ever run".
Admitting that the leadership contest had been "robust and at times difficult", he insisted the debate had nonetheless been "respectful" and the party was agreed on key issues like opposing austerity.
"Now let's turn our agreement into unity, our passion into action and our ideas into reality," he said. "We must win the next general election so Labour can rebuild and transform Britain so no one and no community is left behind. We can and must do that together."