Former health secretary Matt Hancock has apologised for a rule breach after he lobbied the Commons’ standards commissioner during an investigation into a Conservative MP.

Mr Hancock committed the “minor breach” of the MPs’ code of conduct by writing an unsolicited letter to Parliamentary Commissioner for Standards Daniel Greenberg in defence of senior Tory Steve Brine, who was under investigation for allegedly breaking lobbying rules.

The Commons Committee on Standards, while ruling that Mr Hancock did not act with malice over his contact with the commissioner, recommended that the former cabinet minister make an apology to MPs following a review of his behaviour.

The MP, who is currently sitting as an independent after being stripped of the Conservative whip, did so on Monday, telling Speaker Sir Lindsay Hoyle he was grateful to be able to make his statement “at the earliest possible opportunity”.

Mr Hancock told MPs that he had written to Mr Greenberg in March to provide “context to an investigation” the commissioner was carrying out into actions taken by Mr Brine “in response to a Government call-to-arms during the pandemic”.

At the time of the letter, Health and Social Care Committee chairman Mr Brine was under investigation over claims he lobbied the head of the NHS on behalf of a firm for which he was working as a paid consultant.

The details that led to that probe were revealed in the tranche of leaked WhatsApp messages from Mr Hancock, who helped lead the Government’s Covid response as health secretary, published by The Daily Telegraph.

In his correspondence with Mr Greenberg, Mr Hancock said it was his “firm belief” that Mr Brine had been “acting overwhelmingly in the national interest”.

He said Mr Brine “did nothing improper and should be cleared from any accusation given his actions were in line with his duties as a Member of Parliament and British citizen to help our country in its time of need”.

In May, the commissioner concluded that Mr Brine had not properly declared his work for Remedium Partners while contacting Mr Hancock and Michael Gove but cleared him of seeking a financial benefit for the firm, which was offering anaesthetists to the NHS free of charge.

Mr Greenberg, in a memorandum on Mr Hancock’s case, reprimanded the West Suffolk MP for failing to understand the “important distinction between evidence and opinion”.

He added: “Nor has he carefully considered how his opinion about the correct outcome for my inquiry into Mr Brine might put him on the wrong side of the rules laid down by the House.”

Making his apology to the Commons, Mr Hancock said: “The commissioner found that in (writing to him about Mr Brine), I inadvertently committed a minor breach of the House rule that forbids members from lobbying the commissioner or members of the committee over an investigation.

“The Committee on Standards found that I did not seek to break the rules, had no prospect of personal gain and acted without malice.

“However, they recommended that I apologise to the House and the commissioner for this minor breach and underline that respect for the code and the processes of investigating potential breaches of the code is an important and necessary part of the code.

“I’m happy to do so.”

The Commons Committee on Standards said on Monday that, while Mr Hancock had made a “minor breach” of the MPs’ code of conduct, he had yet to acknowledge his mistake.

The committee recommended that Mr Hancock, as well as making a personal statement to apologise to the House of Commons and the commissioner, should also attend a “briefing on his obligations under the code with the commissioner”.

The committee, in its report on his case, said Mr Hancock did not set out to breach the rules, had no prospect of personal gain and did not act with malice by writing to the commissioner.

But it said the former cabinet minister had displayed a “lack of attention to the rules” and “it is concerning that a member with this experience has not taken account of these provisions of the code”.

Mr Hancock had the Tory whip removed in November after agreeing to appear on ITV reality programme I’m A Celebrity … Get Me Out Of Here!

He is due to stand down at the next election, having first been elected in 2010.