Jack McKenna, a former Jeremy Corbyn aide, has been placed under investigation on suspicion of a personal data breach involving another party staff member.
The investigation is said to centre around a now-deleted tweet by a journalist, which referred to a row between Ian Murray, the shadow Scotland secretary, and Labour’s head of policy, Claire Ainsley, about whether one of his aides was going to be fired.
Mr McKenna is accused of breaching ‘personal data’ by allegedly briefing the press about the row – but his allies say there is no evidence for the claim.
Labour said the probe does not amount to a presumption of guilt, reported the Times.
Mr McKenna, who is in charge of Ms Rayner’s media relations and writes her speeches, denies the allegations.
He is now understood to be discussing with his trade union how members of the media became aware of his suspension before he did.
It comes as allies of the deputy leader fear the move is politically motivated amid claims that relations between Sir Keir Starmer and Angela Rayner (pictured together) are now at ‘rock bottom’
Mr McKenna saw Ms Rayner through a recent rocky period, including her apology for branding Tory MPs ‘scum’, as well as her response to sleaze and multiple death threats.
Ms Rayner had reportedly asked him to take a few days off earlier this week, but it is unclear whether she had been aware of his proposed suspension.
It comes as allies of the deputy leader fear the move is politically motivated amid claims that relations between Sir Keir and Ms Rayner are now at ‘rock bottom’ after claims that he had left her ‘humiliated’ and ‘blindsided’ by his surprise reshuffle of Labour’s Shadow Cabinet last week.
But the leader of the opposition has insisted the pair have a good relationship.
‘We’re friends. We get on. We talk a lot,’ he told the Times.
There are fears Mr McKenna’s suspension risks reigniting the civil war between left and moderate factions of the party.
It comes after a bruising stand-off in May which saw Sir Keir try to strip Ms Rayner of some of her shadow cabinet responsibilities – only for her to end up with more.
Mr McKenna was involved in the row as Ms Rayner’s head of communications.
His suspension follows a tough week for the party, which saw key moderates boosted into cabinet positions – including Wes Streeting, Bridget Phillipson and Lisa Nandy – while the likes of Jon Ashworth were demoted.
The Labour Party and Mr McKenna declined to comment when contacted by the Times.
It comes as a senior party figure revealed to The Mail on Sunday yesterday that Sir Keir’s advisers had discussed the extraordinary step of abolishing Ms Rayner’s post.
Jack McKenna, a former Jeremy Corbyn aide, has been placed under investigation on suspicion of a personal data breach involving another party staff member. He denies the allegations.
Ms Rayner’s allies reacted in fury at even the idea of axeing the ‘historic’ post of deputy leader, branding it ‘brutal’ and a ‘constitutional outrage’.
One leading Left-winger claimed it showed that North London MP and barrister Sir Keir was ‘frightened’ and ‘intimidated’ by the outspoken Greater Manchester MP.
The MP said: ‘To even talk about getting rid of his deputy’s post is an outrage and insult to party democracy.’
Moderate MPs hit back by pointing out that it was just two years since Left-wing allies of then leader Jeremy Corbyn had also tried to scrap the deputy position to get rid of then post-holder Tom Watson who was critical of Mr Corbyn.
A senior party insider told the Mail on Sunday that the so-called ‘nuclear option’ of ditching the position was revived earlier this year – including at a meeting attended by Sir Keir.
The idea had been ‘very seriously’ considered, he said, ‘because Keir would feel he had really tried to get on with Angie and it’s proved impossible’.
The insider acknowledged that the change was ‘probably impossible’ because it was ‘such an obviously personal thing’ against Ms Rayner.
He also warned the plan, which would require backing at a party conference, would never be supported by trade union leaders.
Last night, Sir Keir’s spokeswoman denied there had been any discussions on abolishing the deputy leader post or plans to do so.