Jeremy Corbyn is likely to face a single challenger for the Labour leadership after his two rivals held talks about the best way to oust him - but a poll of party members suggested he would still win.
Former shadow cabinet ministers Angela Eagle and Owen Smith have reached a "common understanding" about the best way to take on Mr Corbyn, who won a landslide victory last year.
The decision on which contender gives way will be made once it is clear who has the most nominations from the party's MPs and follows calls from senior figures for a "unity candidate" to stand in the contest.
But in a sign that Mr Corbyn's support within the party's membership remains strong despite the resignations of scores of frontbenchers and an overwhelming vote of no confidence in his leadership from Labour MPs, a poll indicated he would secure a resounding victory over either of his rivals.
The YouGov poll for The Times found that if all three candidates stood, Mr Corbyn would secure 54% of the votes with Ms Eagle on 21% and Owen Smith on 15%.
If Mr Corbyn was opposed by just Ms Eagle, some 58% would vote for the current leader and just 34% for the challenger.
The poll indicated that Mr Corbyn's margin of victory may be slightly narrower if just Mr Smith stood against him - 56% for Mr Corbyn and 34% for Mr Smith - but the result would still be a convincing victory for the incumbent.
Despite the chaos in the Labour ranks, the poll of more than 1,000 party members suggested that 55% of members thought Mr Corbyn was doing well - up from 51% at the end of June.
Nominations from MPs and MEPs opened on Monday evening and close at 5pm on Wednesday, but it may become clear before this time whether Mr Smith or Ms Eagle has the stronger claim to stand against Mr Corbyn.
At a hustings in Parliament Ms Eagle dodged calls by MPs to stand aside if she fails to secure the most nominations - something Mr Smith has promised to do.
But a source close to the leadership race said "productive discussions" had been held between the two contenders resulting in a common understanding.
Both candidates are "focussing on nominations which was always part of the process", the source said.
Former Labour leader Ed Miliband was among senior party figures to call for a single challenger to take on Mr Corbyn.
Speaking at an event in Parliament he told the Press Association: "I think both Angela Eagle and Owen Smith would be excellent candidates.
"So I hope that the process is found to pick one candidate."
Anger at Mr Corbyn's leadership was evident in the Commons as MPs voted to renew the Trident nuclear deterrent system, with Labour splitting three ways. The majority backed the Government's motion, but others - including Mr Corbyn - opposed it and some abstained.
Long-standing anti-nuclear campaigner Mr Corbyn voted against replacing the four submarines which carry the missiles, despite the party's official policy being in favour of maintaining the round-the-clock deterrent.
MP John Woodcock launched a scathing attack on his leader in the House: "For the official opposition to have a free vote on a matter of such strategic national importance is a terrible indictment of how far this once great party has fallen."
:: YouGov polled 1,019 Labour members between Friday and Monday. All those polled had joined Labour before the start of 2016.