John McDonnell has emerged as the joint favourite choice of Labour party members to succeed Jeremy Corbyn as leader, according to a new poll.
The Shadow Chancellor tops the poll along with former Shadow Home Secretary Yvette Cooper, the YouGov/ElectionData survey found.
McDonnell this weekend ruled out ever standing again for the leadership and insisted that Corbyn would lead Labour into the general election.
But the new poll suggests he could come under strong pressure from the grassroots to carry on his friend’s legacy if the leader decides to step aside.
According to the survey, McDonnell and Cooper, who stood unsuccessfully against Corbyn in 2015, are tied on 27%.
Just behind them are Chuka Umunna and Keir Starmer on 26%, Clive Lewis on 23%, Hilary Benn on 21% and Dan Jarvis on 17%.
Cooper - who is the only woman in the top seven names identified in the poll - is currently chair of the Commons Home Affairs Committee.
More widely, Corbyn retains the backing of the rank-and-file membership, with 44% believing he should lead the party into the next general election, compared to 36% who think he should step down now.
A further 14% think that he should continue to lead Labour “for the time being” but also that he should resign before the next election.
McDonnell, who stood for the leadership against Gordon Brown in 2007, is seen by many of his supporters as a crucial ally of Corbyn in his bid to represent party members.
According to the poll - commissioned by former Ed Miliband pollster Ian Warren - McDonnell is has a big lead among party members who joined since Corbyn’s first leadership campaign started in 2015.
In the past couple of years, Labour’s membership has soared to more than half a million - making it the biggest party in Western Europe - with many joining to power Corbyn’s two landslide election victories.
The Shadow Chancellor, backed by grassroots left-wingers, has tabled a change in party rules to lower the number of MPs’ nominations needed for any future leadership bids.
The plan, set to be debated and voted on at this year’s annual conference, is seen as a way to break the usual stranglehold the Parliamentary Labour Party (PLP) over leadership contests.
McDonnell told the Andrew Marr Show on Sunday that the changes were academic because he believed Corbyn would still lead the party at the next election.
“I want to be absolutely clear. John McDonnell will not stand for the Labour leadership ever in the future again. Full stop,” he said.
“I’ve campaigned for lowering the threshold for years but it’s not that significant to me because Jeremy Corbyn will lead us into the next election.
“Of course we’re building up a succession for the long term future and we’ve got some really great young talent coming through but they need more experience before, eventually they will succeed.”
If there was another leadership election today, Corbyn looks set again to romp to victory, as he polls 40% in any contest, with Cooper way behind on 25%, and Umunna and Starmer on 24%.
But the poll suggests that the Labour leader’s support has fallen in the past year, as his net approval rating has fallen from +55% in February 2016 to +17% in February 2017.
Corbyn was also blamed by 41% of party members as being the main reason for Labour’s historic loss of the Copeland by-election to the Tories last month.
Yet 34% of members felt the media was more to blame, 22% felt Tony Blair’s critical speech the week before polling day was the main cause, and 20% felt that outgoing MP Jamie Reed was most responsible.
Some Labour MPs believe that party members are “on a journey” towards realising that Corbyn’s poor national poll ratings among the wider public mean he will never become Prime Minister.
The YouGov/ElectionData poll shows that just 35% of members think it was now likely he would win the keys to No.10, compared to 56% who think it is unlikely.
A year ago the figures were markedly different, with 47% saying it was likely Corbyn would become PM, and 41% believing it would unlikely.