Aides to Jeremy Corbyn and John McDonnell have been cleared of breaking Commons rules when entering the office of former shadow Cabinet minister Seema Malhotra.

John Bercow, Speaker of the House of Commons, told Malhotra there was “nothing” in her complaint which added up to a breach of parliamentary privilege.

Malhotra had claimed at the weekend that staff working for the leadership had made an “unauthorised” entry into her office – prompting another internal row as the former shadow Chief Secretary accused the Corbynistas of “violating” her privacy and security.

Now, after studying her complaint, and asking the deputy Serjeant at Arms to seek more information, Bercow has written to Malhotra to say the rules have not been broken.

In what could be seen as a pointed reference to tensions in the Labour Party, Bercow went on to say that MPs and staff should operate in a “regime of mutual respect”.

The row prompted deep dismay that another internal dispute had dominated television and newspaper headlines and also led to a dramatic direct-to-camera appeal by John McDonnell in which he told Labour’s warring factions to “stop this now”.

Last night McDonnell attacked his former deputy and said the disagreement was part of the plan to weaken Corbyn.

“It’s only right and fair that Seema now apologises for the stress she has caused to my staff over the last few days. As I said on the Andrew Marr Show on Sunday the Labour Party needs to unite and actions like this which are only being used to try to undermine Jeremy Corbyn’s leadership must stop.”

Malhotra told the BBC: “I welcome the Speaker’s statement that ‘nobody should enter a Member of Parliament’s office or the office of their staff, locked or unlocked, without their permission’. This vindicates my view that what happened should not have happened.

“My staff have been distressed by what has happened. I regret the distress that has been caused on both sides. But I come back to what this is all about: our office was entered without our knowledge and without my permission.

“And the Speaker has ruled today that should not happen.”