Labour’s Jon Trickett has written to the Cabinet Secretary and head of the civil service today, calling for an independent investigation into an apparent breach of civil service neutrality.

A story by The Times on Saturday featured briefings from two senior civil servants, who suggested that Jeremy Corbyn may be “too ill” and “frail” to be Prime Minister or even Labour leader. “There must be senior people in the party who know that he is not functioning on all cylinders,” one was quoted as saying.

As shadow minister for the Cabinet Office, Trickett has therefore asked Mark Sedwill for a personal meeting to discuss the matter and for an investigation that would be “independent of the Cabinet Office”. In his letter, the Labour frontbencher describes the incident as an “unconstitutional political intervention with disturbing implications for our democratic system”.

Responding to The Times splash yesterday, Corbyn said: “The idea that civil servants should be briefing a newspapers against an elected politician, against a prospective government, is something that should be very concerning to all of us.

“The Civil Service has to be independent; has to be non-political and has to be non-judgmental of the politicians they have a duty to serve. If we were elected to government, we have a very clear framework of things we want to do in this country on housing, education, health and the environment and so much more. We would explain those to our colleagues in the civil service and expect them to carry out those policies.

“That is the way British democracy must work. There must be an investigation into which senior civil servants are spreading fictitious information to the press and in the process compromising the integrity of the Civil Service.”

Below is the full text of Jon Trickett’s letter to Mark Sedwill.

Dear Mr Sedwill

I am writing in connection with the articles today in The Times on Saturday, which you will have seen.

These pieces offer a credible account of conversations at a senior level in the civil service about the Leader of the Opposition, the Rt Hon Jeremy Corbyn MP.

The premise of these conversations is the allegation that Mr Corbyn’s health is poor. This is manifestly untrue.

Discussion of these matters, based on false assumptions, should not be taking place. Worse, it is without precedent in my experience that any high-level discussion about senior politicians, let alone the leader of the Opposition, should be shared with a newspaper.

I must now formally say to you that it is hard to avoid the conclusion that this has been a totally unwarranted and indeed unconstitutional political intervention with disturbing implications for our democratic system.

There clearly needs to be an investigation into what appears to have been a breach of civil service neutrality, independent of the Cabinet Office, in order to avoid any real or apparent conflicts of interest.

I am also writing formally to request a meeting with you to discuss this deeply concerning development, when I hope you will be able to give clear assurances that the basic principles of British public life will not be undermined.

I look forward to hearing from you.

Jon Trickett MP

Shadow Minister at the Cabinet Office