Mark Garnier, the international trade minister, will be allowed to keep his job in government after being cleared of wrongdoing by a Cabinet Office investigation.

The Tory MP for Wyre Forest called his ex-assistant “sugar tits” in front of others in a bar in 2010 and asked her to buy two sex toys from a Soho shop.

Garnier, a married 53-year-old father-of-three, claimed he was friends with the woman and the incidents have been taken “outside the context”.

Downing Street said the investigation found Garnier had not broken the Ministerial Code.

No.10 said Theresa May believed “a line should be drawn under” the issue as it was “not his intention to cause distress”.

Garnier escaped punishment the day after May fired her close ally Damian Green for lying about knowing of the existence of porn on his office computer.

In its statement on Friday about Garnier, Downing Street said: “Following allegations of sexual misconduct, the Prime Minister asked the Cabinet Office to look into the behaviour of Mark Garnier MP, Parliamentary Under Secretary of State at the Department for International Trade. The Cabinet Office’s investigation primarily considered Mr Garnier’s behaviour as a Minister, but also heard evidence from before he was appointed to government.

“The Cabinet Office concluded that there was no evidence to suggest that Mr Garnier’s conduct as a Minister since 2016 had breached the expected standards of behaviour. The Prime Minister’s view is therefore that Mr Garnier did not break the Ministerial Code while holding government office.

“The Cabinet Office also took evidence in relation to an incident that happened before Mr Garnier was a Minister, between Mr Garnier and a member of his parliamentary and constituency staff.

“The Cabinet Office concluded that there was no dispute about the facts of the incident, but there was a significant difference of interpretation between the parties, and that the member of staff in Mr Garnier’s office was distressed by what had occurred.

“It was not his intention to cause distress, and Mr Garnier has apologised unreservedly to the individual. On that basis the Prime Minister considers that a line should be drawn under the issue.”