Jeremy Corbyn needs to show that he can win round public opinion within the next 15 months to retain the party’s support, his most powerful union supporter, Len McCluskey, has suggested. The Unite general secretary became the latest figure in the party to issue what sounded like a coded ultimatum as he hit back at allegations that his union was conspiring with Momentum to take over Labour.

Speaking on Radio 5 Live’s Pienaar’s Politics on Sunday, McCluskey acknowledged that Labour’s current standing in the opinion polls was poor, but he said he hoped that Corbyn would be able to turn the situation around before next year’s local elections.

“The reality is that I’m hoping [Corbyn’s] given the opportunity to put the alternative that Labour are building to the British electorate and hopefully we’ll see, if he can break through, the opinion polls begin to change,” McCluskey said. “I would suggest that the next 15 months or so will give us the answer to that.”

Secret tape reveals Momentum plot to seize control of Labour Read more

Some of Corbyn’s other close allies, such as John McDonnell, the shadow chancellor, and Diane Abbott, have also spoken about Labour needing to show by 2018 that it is recovering, although more recently McDonnell has revised his assessment and said that bouncing back could take two years. What might happen if the recovery does not occur within that timescale has largely been left unsaid.

In his interview, McCluskey criticised Tom Watson, the Labour deputy leader, who alleged last week that a tape uncovered by the Observer showed that Unite and the pro-Corbyn Momentum organisation were involved in “a hard-left plot by supporters of Corbyn to seize permanent control of the Labour party”.

McCluskey said these were “smears and lies” and that the allegations were straining the relationship between unions and the party. “My members don’t vote to affiliate to the Labour party so they can be abused by certain Labour leaders,” he said. In a separate interview on Sunday, Corbyn said the idea of a pact between Unite and Momentum was “fiction”.



But Sir Keir Starmer, the shadow Brexit secretary, defended Watson. Speaking on the BBC, Starmer said Watson had been “quite right” to speak out about the tape, which showed the head of Momentum, Jon Lansman, telling supporters that McCluskey planned to affiliate Unite to Momentum if he was re-elected as the union’s general secretary.

Ballot papers for the contest will go out this week. McCluskey has been elected twice before, but this year he is facing a strong challenge from Gerard Coyne, who has accused McCluskey of devoting too much time and money to propping up Corbyn.

Coyne said: “Who is Len McCluskey to decide that Jeremy Corbyn has 15 months to prove himself? He claims to run a democratic union, but he never asked ordinary Unite members in the first place who they thought would be the best Labour leader.”

The third candidate in the Unite contest is Ian Allinson, who is standing as a “grassroots socialist”.