Shadow international trade secretary Barry Gardiner has confirmed he is “considering” a late bid for the Labour leadership.
The Brent North MP, who has developed a following on the left of the party for his defence of Jeremy Corbyn’s policies, would be the seventh candidate to declare if he formally enters the race.
Asked whether he is intending to stand for Labour leader, Mr Gardiner told the PA news agency he is “considering it at present”.
Such a move could damage support for shadow business secretary Rebecca Long-Bailey, who has tried to position herself as the standard bearer for the left.
Unite union boss Len McCluskey denied reports that he is trying to get Mr Gardiner to declare for the contest.
This is utter nonsense. I certainly haven't been approached by Barry to support him as leader. Let me also make clear I have not indicated any concerns about RLB's campaign, or anyone else's. 1/1 https://t.co/noXKDBcAio
— Len McCluskey (@LenMcCluskey) January 8, 2020
Mr Gardiner held government roles under Tony Blair and Gordon Brown, voted for the Iraq War in 2003 and backed David Miliband as Labour leader in 2010.
Meanwhile, early front-runner Sir Keir Starmer met union backers on Thursday in a bid to maintain his edge in the competition.
The shadow Brexit secretary said Labour needs to regain the trust of voters after its “devastating” defeat in December, as he visited the headquarters of Unison – the first of the big unions to declare for him.
“I do believe that we can be an effective opposition, that we can take the challenge to Boris Johnson, that we can restore trust in our party,” he added.
“But we can only do that if we unite, if we put factionalism on one side.
“Divided parties don’t win elections, united parties win elections. I want to be able to pull our party together so we are all in one team batting together.
“We have lost four elections in a row. If you lose an election you are in opposition, if you are in opposition you are not changing lives. So we have got to focus on forging that path to victory.
“You do that not by trashing the last Labour government, not by trashing everything that has happened since 2015, but by focusing relentlessly on the future.”
Would-be candidates have until Monday to secure backing to make it into the second round of the battle which will see the new leader announced on April 4.
Sir Keir was the first to receive the backing of enough Labour MPs to enter the second round.
He is well ahead in MP endorsements of his main rival, Ms Long-Bailey, who has been dubbed the “continuity Corbyn” candidate by some.
Other contenders to declare for the top job are shadow foreign secretary Emily Thornberry, shadow Treasury minister Clive Lewis, and backbenchers Jess Phillips and Lisa Nandy.
After Ms Long-Bailey gave Mr Corbyn a 10 out of 10 score for his leadership, Ms Thornberry gave him a zero rating for his electoral performance.
She gave him no more than a two out of 10 rating for tackling anti-Semitism, but top marks for his ability to enthuse the Labour movement.
“Losing an election is probably the most important thing by which you would measure a leader and obviously we lost very, very badly,” she told Sky News.
“On that basis I would give him, on that, nought out of 10. What else could I do?”
Meanwhile Ms Nandy picked up an endorsement from former Scottish first minister Lord McConnell.
Candidates need nominations from 10% of Labour MPs and MEPs, who total 212, making the required threshold 22.
Contenders who receive enough nominations will enter phase two of the contest, where they have to secure the backing of 5% of constituency Labour branches or at least three affiliate groups, two of which must be made up of trade unions, to get on the final ballot paper to go to the membership.