LABOUR’S civil war continued unabated yesterday with allegations of bullying levelled at Jeremy Corbyn and a claim from a union boss that abuse aimed at the party leader’s critics could be the work of the security services.

Unite union boss Len McCluskey, a key Corbyn ally, said the security services had a history of “dark practices” and suggested “right-wingers” in disguise might be responsible for actions blamed on Corbyn supporters.

“Do people believe for one second that the security forces are not involved in dark practices?” he said in a national newspaper interview.

“We found out just a couple of years ago that the chair of my union then, the Transport and General Workers Union, was an MI5 informant at the time that there was a strike taking place that I personally, as a worker, was involved in”, he added.

“(In) 1972, I was on strike for six weeks. And 30 years later it comes out that the chair of my union at that time was an MI5 informant.

“Anybody who thinks that that isn’t happening doesn’t live in the same world that I live in. Do you think that there’s not all kinds of right-wingers who are not secretly able to disguise themselves and stir up trouble? I find it amazing if people think that isn’t happening.”

McCluskey accused MPs and others in the party who had complained of death threats and intimidation of exaggerating the problem.

“There’s a hysteria being whipped up. A few people say things they shouldn’t and then it’s blown up out of all proportion, to suit the imagery that the Labour Party has somehow become a cesspit, and suddenly it’s a crisis,” he said.

McCluskey’s comments came after Corbyn rival Owen Smith said the party leader had allowed a “culture of bullying” to take hold and that “something had gone badly wrong” since he took charge. Corbyn insisted he was not a bully and said he was “disappointed” at the claims made against him, which included a suggestion he threatened to ring the father of MP Conor McGinn - a Sinn Fein councillor - in an effort to “bully” him after critical comments the MP made in a magazine interview.

Smith warned the party could be “destroyed” and “consigned to history” unless it could unite. He said he had received death threats, but accepted he had “never been bullied by Jeremy” personally, although he added that “under his leadership, there has been a culture of bullying”.

Smith added: “Jeremy, of course, always says that he doesn’t condone it but somehow under his leadership - we can’t deny the facts that this wasn’t something that we saw in the Labour Party before Jeremy Corbyn became leader - and it’s now become commonplace in the Labour Party. So something has gone badly wrong under his watch.”

Former leadership contender Angela Eagle, who stood aside to give Smith a clear run, claimed she had been the victim of organised bullying.

The day after she announced she was to challenge Corbyn, a brick was thrown through a window of the building where her constituency office is based. Her local constituency party was suspended this week amid allegations of bullying.

Last week a man in Paisley, Renfrewshire, was arrested on suspicion of threatening to kill Eagle. He has since been released on police bail.

“These are serious issues,”said Eagle. “Rape threats, death threats and organised bullying are not something to be ignored or minimised.”

She said she was cancelling public meetings in her Wallasey constituency on police advice - although Merseyside Police later said it had been the MP’s decision to do so.

Corbyn is favourite to win the postal ballot of Labour’s members - whose ranks he said have swollen to more than 500,000 - as well as the 183,000 people who signed up this week as registered supporters and the affiliated supporters in the unions.

Addressing Eagle’s and McGinn’s allegations, he said: “I wish some of my colleagues would concentrate on political issues. I regret the language that’s been used, by all of them.

“I don’t do any abuse, I don’t do any bullying, I don’t allow it to be done anywhere to do with any of my campaign teams and I’m very surprised and very disappointed they should say that because politics has to be about bringing people in.”