Emily Thornberry is being backed by Unite boss Len McCluskey to become Labour’s first woman leader, HuffPost UK can reveal.
The general secretary of the UK’s biggest trade union has told friends that he thinks Thornberry is a unifying figure who can carry on Jeremy Corbyn’s work when he eventually decides to step aside.
The Shadow Foreign Secretary already stands in for Corbyn at Prime Minister’s Question Time and has built up a fanbase within the rank and file membership for her loyal defence of the leader over the past year.
Winning the backing of Unite’s general secretary, as well as other unions, could prove crucial in any future leadership contest once Corbyn decides to make way for a new generation.
Thornberry is also being touted in the interim as a possible deputy leader by left-wingers who want to create a female-only post to counterbalance the role of current deputy Tom Watson.
One senior source told HuffPost UK that McCluskey had made clear his views at a recent private meeting.
“Len’s admiration for Emily is evident and longstanding. He sees her as a tough cookie who isn’t afraid of taking big decisions.
“Of course, there is no vacancy and there won’t be for the foreseeable future. Len totally backs Jeremy and wants him to be Prime Minister.
“But the next Labour leader after Jeremy has to be a woman and Len believes Emily is a unifying figure.”
McCluskey told fellow union leaders in the run up to the June election that if Corbyn did badly and was forced out Thornberry should be a strong contender to replace him.
Thornberry impressed many in Unite when she delivered a speech at a Commons reception hosted by the union for all the MPs it sponsors in Parliament.
In an interview with HuffPost UK to be published on Thursday, Jeremy Corbyn made clear how impressed he was with his de facto Parliamentary deputy.
“Emily is great. We keep in touch all the time obviously and on the small number of occasions when someone else does PMQs, I get to watch from home or from my office,” he said.
“I think she has performed extremely well.”
The former barrister was appointed by Corbyn to the Shadow Cabinet as Shadow Defence Secretary, replacing the pro-Trident Maria Eagle. She subsequently upset some in the Parliamentary Labour Party (PLP) by suggesting alternatives to renewal of the Trident nuclear deterrent.
She was again promoted to Shadow Foreign Secretary after Hilary Benn quit in 2016, a move that sparked the failed ‘coup’ and mass resignations by shadow ministers in a bid to oust Corbyn.
As a fellow Islington MP, Thornberry has long been supportive of the veteran leftwinger and the pair jointly celebrated 2017 general election night at their local count, when they both saw their majorities soar thanks to the ‘Corbyn surge’.
Thornberry has been key to shifts in Labour’s foreign policy, including a tougher line on arms sales to Saudi Arabia, standing up to Donald Trump on climate change and Syria, and promoting human rights around the world.
Her recent stints deputising for Corbyn at PMQs have won her a new audience, and she delighted Labour members in the election when she ambushed Defence Secretary Michael Fallon on the Andrew Marr Show over his Syria links.
McCluskey is another loyal supporter of Corbyn, standing by him last year when senior Shadow Cabinet ministers urged him to quit in the wake of the Brexit referendum vote.
Unite was also Labour’s main source of large donations in the election campaign, funding key seats and targeting more than a million of its members to mobilise the party’s vote.
A Unite spokesman refused to comment on Thornberry but said: “Len McCluskey backs one leader of our party and one leader only and that is Jeremy Corbyn. Unite’s every focus is on getting a Corbyn-led government into No 10 and seeing the end of this miserable Conservative administration.”
Corbyn’s position as leader is seen as secure for the rest of the Parliament given his success in increasing Labour seats in the election and in denying Theresa May her Commons majority. But his allies are keen to line up a successor to entrench his leftward shift in policy and in engaging the mass membership.
Thornberry is a close ally of Diane Abbott and Shami Chakrabarti but also has admirers among Labour MPs who strongly backed Gordon Brown and Ed Miliband.
Her earthy use of language has won fresh admirers, including telling Fallon he was ‘talking bolllocks’ about claims Labour would hand the Falklands to Argentina. She has also mouthed the same word at David Cameron in previous PMQs.
Thornberry’s critics point out that she would be another London-based Labour leader, although her supporters counter that her record proves she can continue Corbyn’s transformation of the party.
The Islington South MP is one of the “fab five” in the Shadow Cabinet that senior aides to Corbyn want to promote at the coming party conference in Brighton, while giving members more time for debate. Others are John McDonnell, Diane Abbott, Keir Starmer and Corbyn himself.
Thornberry’s popularity in the party has steadily grown since the ‘St George’s flag’ row, when she was forced out by Ed Miliband for tweeting a photo from Kent that was interpreted as being out of touch with working class voters.
Critics of Watson, who won his own large mandate in the deputy leadership election of 2015, want the party to create a second female-only post of deputy leader to dilute his influence.
But the plan would require a rule change by party conference and no proposals have yet been distributed to the ruling National Executive Committee for next month’s gathering in Brighton. The rule change may be drafted for the 2018 conference in Liverpool instead.
Others in the party believe that Shadow Education Secretary Angela Rayner would have a stong chance in any deputy leader election, but some allies of Corbyn see Thornberry as the better choice.
Watson, who last year warned his leader that Labour needed to win power to have any effect, has already shifted his stance and made clear to Corbyn that he won’t stand in his way at the 2017 conference or NEC meetings.
However, some Unite members are expected at conference to vent their anger at the deputy leader for what they see as his backing of Gerard Coyne, McCluskey’s defeated challenger for the general secretary post.
McCluskey and Watson were once close but have fallen out spectacularly in recent years. Watson warned in March that an alliance between Unite and grassroots group Momentum could ‘destroy’ Labour.
McCluskey hit back in a HuffPost UK blog that Watson lived “in a world of skulduggery, smears and secret plots”.