The head of the civil service has been asked to investigate claims that one of the Home Secretary's advisers briefed newspapers against the former head of the UK border force Brodie Clark.
Mr Clark was named in articles last Saturday as being the civil servant responsible for "abandoning immigration checks at airports" for non EU residents entering the UK. A senior source was quoted by a newspaper saying "criminal charges" could be brought against anyone found to have put Britain's borders at risk.
It was also revealed that Mr Clark had already been suspended by Theresa May for relaxing immigration controls beyond agreed limits and quoted her as being "furious". Mr Clark later resigned, saying his position had been made "untenable". He denies acting improperly and says he is planning to sue for constructive dismissal.
Yesterday the Labour MP Simon Danczuk wrote to Sir Gus O'Donnell asking him to investigate whether Ms May's special advisers had been responsible for the unattributable briefings.
It is understood that at least one newspaper had found out about the change in border controls – and it is suggested Mr Clark may have been blamed to deflect attention away from Ms May.
In his letter to Sir Gus – which was also sent to Mrs May – Mr Danczuk said: "I am writing to raise serious concerns about suggestions that advisers to the Home Secretary may have been briefing against a serving civil servant who had been suspended and therefore had no right to reply."
He referred to claims that officials had been told to refuse any offer of resignation by Mr Clark, as well as descriptions of him as a "rogue civil servant".
The Rochdale MP went on: "If the information about Mr Clark, who at that time was still suspended and had not resigned, came from one of the Home Secretary's special advisers, then this appears to be a breach of the code [of conduct for special advisers]."
The code of conduct states that "the preparation or dissemination of inappropriate material or personal attacks has no part to play in the job of being a special adviser as it has no part to play in the conduct of public life".