Theresa May: First I learned of Damian Green claims was when Kate Maltby wrote in Times

However, speaking to reporters during a visit to British troops in Cyprus, the Prime Minister said she had not been informed of the claims.

“The first I learned of these allegations was when Kate Maltby wrote about them in The Times,” she said.

Ms Maltby, who is three decades younger than Mr Green, claimed he “fleetingly” touched her knee during a meeting in a pub in 2015, and a year later sent her a “suggestive” text message after she was pictured wearing a corset in a newspaper.

The allegations, which Mr Green says he does not recognise, triggered a Cabinet Office probe into his conduct.

That led to Mrs May sacking her de facto deputy after he made “misleading” statements about allegations that police found pornography on computers in his parliamentary office in 2008.

The Prime Minister said: “I recognise that Kate Maltby was obviously extremely distressed by what happened. Damian Green has recognised that and he has apologised. I think that is absolutely the right thing to do.”

The Daily Telegraph reported that Ms Maltby told a Downing Street aide about her claims against Mr Green in September 2016, and she was informed it was part of a pattern of behaviour, and that “the Prime Minister knows”.

Ms Maltby told the newspaper: “I would never, never have told my story about Damian Green if I did not believe I was exposing a pattern of behaviour of which I thought the Prime Minister was personally aware.”

Ms Matlby told the BBC: “The reason that I didn’t tell many people about the first encounter, the encounter which I felt the political mentorship, or even a job in the Conservative Party, was being offered at the same time as a sexual suggestion. The reason I didn’t tell many people then, except my parents, is that I wondered if it was a one-off … and, eventually, I spoke to a very senior and long-serving aide of Theresa May.”

Theresa May asked Damien Green to resign (Philip Toscano/PA)

Asked if she had told the Cabinet Office investigation, headed by senior civil servant Sue Gray, that Downing Street was aware “there was an issue” with Mr Green’s behaviour towards women, Ms Maltby said: “I gave evidence to the inquiry, as soon as I sat down with Sue Gray, that, to the best of my knowledge, Downing Street was aware.

“But this whole story has been about power imbalances. This whole story is about power. Damian Green became a very, very powerful person. I was aware that there seemed to be … an improper mixing of mentorship and sexual advance within the Conservative Party.”

A Downing Street source said: “The Cabinet Office conducted a thorough investigation into a number of allegations about Damian Green. The inquiry findings were published yesterday.

“The PM has made it clear that everyone should be able to work in politics without fear or harassment – that is why she has brought forward a new Code of Conduct for the Conservative Party, and set up a cross-party working group to make recommendations about the Houses of Parliament.”

Reporting the probe’s findings, Cabinet Secretary Sir Jeremy Heywood said that with “competing and contradictory accounts of what were private meetings” it was “not possible to reach a definitive conclusion on the appropriateness of Mr Green’s behaviour with Kate Maltby in early 2015, though the investigation found Ms Maltby’s account to be plausible”.

When Mr Green left office on Wednesday he said he did not recognise Ms Maltby’s version of events, stating: “I deeply regret the distress caused to Kate Maltby following her article about me and the reaction to it. I do not recognise the events she described in her article, but I clearly made her feel uncomfortable and for this I apologise.”