Roy Hattersley, Labour’s former deputy leader, has reignited the party’s feuding by claiming it is “in danger of disintegration” as extremists take over.

Labour is in “a much more dangerous situation” than during the Militant Tendency insurgency of the 1980s because left-wing activists are “increasingly in control” he claimed.

Lord Hattersley said the public was suspicious that “the people behind Jeremy will take over the party and run it in a way which we find unacceptable” – putting hopes of an election win “in difficult trouble”.

Moderate party figures with “sense” had to speak out, he argued, describing it as a “tragedy for the Labour Party” that they remained silent about what was going on.

The peer, deputy to Neil Kinnock in the 1980s, also attacked Mr Corbyn for failing his “democratic duty” to fight Brexit, calling for a referendum on the final withdrawal terms.

On the Corbynista takeover, Lord Hattersley said: “I think the Labour party is in a much more dangerous situation than it was in the 1980s.

“In the 1980s there was entryism, there was the Militant Tendency, but they only operated in one or two small constituencies. They didn’t control the machine, they certainly didn’t control the leader, there were trade unions who were prepared to stand out against them and we always knew that the battle in the 1980s would eventually be won.

“Now things are much more serious because people who are not ‘real Labour’ as I define it are increasingly in control of the machine, they’re increasingly taking over constituencies, they’re increasingly bullying moderate MPs. And if it goes on like this the Labour party is in danger of disintegration.”

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In the interview for BBC Radio 4’s Westminster Hour programme, Lord Hattersley warned against deselecting hard-working MPs, amid a left-wing push for compulsory constituency ballots.

“If two or three of those are deselected, then I think mayhem follows because other members of parliament will be nervous, other members of parliament will be resentful and then we start talking again about the disaster of a split and a third party,” he said.

The interview comes after fierce internal criticism of Mr Corbyn for refusing to blame Russia for the Salisbury nerve agent attack and for failing to tackle antisemitism in the party.

Meanwhile, the Left of the party has secured control of its ruling NEC committee and the election of Mr Corbyn’s ally Jennie Formby as the new general secretary.

Lord Hattersley backed Labour’s 2017 manifesto as “a perfectly sensible, workable manifesto”, but said the party should be firmly ahead in the opinion polls – which still have the two big parties neck-and-neck.

“The problem is the hovering suspicion that somehow the people behind Jeremy will take over the party and run it in a way which we find unacceptable,” Lord Hattersley said. “And, unless he can overcome that suspicion, then we’re in difficult trouble as far as winning an election is concerned.”

On Brexit, Lord Hattersley said: “There’s no doubt at all that a majority of Labour Party members, the majority of Labour supporters, want to remain in the European Union.