Labour’s leadership challenge against Jeremy Corbyn was up in the air on Thursday morning after plans for Angela Eagle to trigger the contest came up against an alternative pitch from the former shadow work and pensions secretary Owen Smith, who has collected nominations from dozens of MPs.

Sources say that Eagle, who also resigned from her shadow cabinet position, is meeting Smith so that the party can agree on a single candidate, with MPs on both sides pushing hard for their preferred choice.

Allies of Eagle insisted that she remained the unity candidate who had support across the party, and accused Smith of “scrabbling” for nominations at the last moment.

But some MPs have told the Guardian they believe Smith has the better prospect of beating Corbyn because he is further to the left politically. They also fear Eagle could be attacked by the leader’s supporters because the Chilcot inquiry will be published next week, and she voted in favour of the invasion of Iraq in 2003.

Eagle’s supporters dismissed the suggestion, pointing out that Iraq was an issue for lots of politicians, including Smith, who was an adviser to the MP Paul Murphy, who also voted for the war.

One senior MP, who has also resigned from Labour’s top team, told the Guardian: “It is yet to be resolved, but lots of support [is] moving Owen’s way.” They argued that Smith could win the “soft left”.

“In general there is lots of disquiet that [Eagle] might unilaterally declare. PLP [the parliamentary Labour party] feel strongly that we should take a collective view about who can beat [Corbyn], not simply one person who just decides to declare themselves.”

When writing for Guardian, the popular Labour MP Lisa Nandy, hinted that the search was still on for a unity candidate, although it was not clear whether she thought Eagle would fit the bill.

She wrote: “The battle lines in the leadership contest have been drawn, and both sides have signalled they are unwilling to stop. In taking this path we are consigning ourselves to irrelevance at a time when the sensible majority in the country – who want to see a sensible, measured, respectful conversation focused on the things that unite us – desperately need a voice.”

But Eagle was certainly seen as a frontrunner along with the deputy leader, Tom Watson, before he ended speculation by saying he would not challenge Corbyn directly, and still wished his leader would resign. At that point a large number of MPs seemed to be happy with either of the two candidates.

“Angela has support from all wings of the party to be a strong unity candidate. There is a time for calm and careful thinking for the sake of the country and our party. The party needs to unite - late-night egos on the terrace of the Commons are not the way forward,” said a politician backing Eagle.

Meanwhile, the party’s national executive committee will meet to vote on whether Corbyn ought to be automatically placed on the ballot or if he will have to collect the nominations of MPs.



One piece of legal advice, leaked to the Guardian, suggests that he does not need support, but can simply run again. But NEC sources have suggested that there is a second document, which has not been seen, showing the opposite, with many pointing to a 1980s contest in which Tony Benn challenged the leader, Neil Kinnock. They point out that Kinnock was expected to collect nominations.

