Six of the seven probable challengers are female, and all will be keen to connect with traditional party supporters

The battle to succeed Jeremy Corbyn and shape the future direction of the Labour party is under way as potential successors set out their leadership stalls for the first time, amid bitter recriminations after the party’s worst general election defeat since 1935.

Two of the likely candidates in what will be a 12-week contest that is expected to begin in January – Jess Phillips and Lisa Nandy – break cover with articles in the Observer, expressing their anger and dismay at the party’s crushing defeat, and calling for a far-reaching post-mortem to ensure Labour reconnects with the millions of working people who rejected it.

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Seven MPs, six of them women – Phillips, Nandy, Emily Thornberry, Rebecca Long-Bailey, Angela Rayner and Yvette Cooper – are understood to be thinking of joining the contest, making it likely that Labour will for the first time elect a female leader. Keir Starmer, the shadow Brexit secretary, is also likely to join the race.

In the early hours of Friday, when the scale of Labour’s defeat was known, Corbyn announced that he would not lead Labour into another election but would stay to allow the party a period of “reflection” until a new leader was elected.

While many MPs have attacked him for refusing to go sooner, and for his initial refusal to apologise personally for the crushing loss, others argue that the party should avoid a bitter blame game.

In what appears to be a pitch for the top job, Phillips argues that the party must broaden its appeal so it can once again attract a coalition of support from both the working class and middle classes. But she goes out of her way to insist that she is not advocating a return to the approach of New Labour.

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“Some call me a Blairite because I’m evangelical about the difference Sure Start and tax credits made to my life. But I marched against Iraq, I didn’t even become an MP until eight years after he’d left parliament, so how does that fit?”

She is severely critical of the way Corbyn and his supporters have seized control of the party machine and excluded those with different views. “The truth is there are corners of our party that have become too intolerant of challenge and debate,” she writes. “There is a clique who don’t care if our appeal has narrowed as long as they have control of the institutions and ideas of the party.

Play Video 2:19 Jeremy Corbyn says he will stay as Labour leader until next year – video

“We’ve all got to discover the courage to ask the difficult questions about the future of our party and the future of the working class communities who need a Labour government.”

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Nandy also argues that the party has “lost touch with the day-to-day lived experience of many of the people we want to represent” and must reconnect with them by listening and becoming more “rooted in our communities”. Only that way could Labour understand the practical needs of working people and respond to them.

Also writing in the Observer today, Corbyn says there is “no doubt” about the popularity of Labour’s policies. However, Nandy says that some of the manifesto made little sense. “Nationalising rail is a good, sound policy, but should we have staked so much of our campaign on that policy when so many of the towns we lost have no train station and rely on buses anyway? Should we really be rejecting nuclear power when it is one of the best sources of good jobs outside of London?”

On Saturday senior Labour figures said that Long-Bailey, the shadow business secretary, was already being promoted by the Corbyn circle as his favoured successor.

Sharp differences of view were expressed over whether Corbyn should continue as leader for the next few months or go sooner.

Facebook Twitter Pinterest Jess Phillips, Keir Starmer and Emily Thornberry are the other three likely contenders. Composite: Rex/Shutterstock

Peter Kyle, who held his Hove and Portslade seat comfortably, said action to purge the entire Corbyn leadership was needed immediately. Writing in the Observer, he accuses Corbyn and his inner circle of betraying Labour members with a “culture of authoritarianism, bullying, and organisational incompetence”. He adds: “We must move forward, fast. Tom Watson has gone, Jeremy is going, and Len McCluskey [the Unite general secretary] must follow.” Other MPs said Labour had to have a new leader in place before campaigning starts in Spring ahead of May’s local elections.

But , also writing in this paper, Labour MPs Lucy Powell and Shabana Mahmood, who held their seats of Manchester Central and Birmingham Ladywood, urge the party not to indulge in a bitter blame game, and instead to work together to learn the lessons for the long term.

“Our starting point for a Labour recovery can’t be to pick the things we like and blame the things that we don’t. Some want to say our defeat was all about Jeremy Corbyn, others that it was only Brexit. Both are wrong. It’s clear that our losses were about both and much, much more.

“We must now undertake a real and meaningful review with everything on the table, and no no-go areas. It must start from a place of humility which acknowledges Labour got it wrong rather than the voters, with a process that involves the whole of our movement, and those who feel we’ve left them behind.”

Angela Eagle, who retained the Merseyside seat of Wallasey, said there were many people at the top of the party, including senior officials and advisers, who needed to think seriously about whether it was credible for them to carry on after the election disaster. “There are a lot of people who need to reflect and consider their positions, not just the leadership in parliament.”

Corbyn will face a difficult few days after parliament returns on Tuesday. He is expected to address a meeting of the parliamentary party that day, then taking part in prime minister’s questions on Wednesday, before accompanying Johnson on the traditional walk from Commons to Lords on Thursday for the Queen’s speech.