Mark Garnier: Wyre Forest MP facing investigation over claims he asked his secretary to buy sex toys

Theresa May ordered the inquiry into whether International Trade Minister Mark Garnier breached ministerial rules following allegations he used derogatory language to his secretary and asked her to buy sex toys.

The Prime Minister has also written to Commons Speaker John Bercow, asking for the establishment of a new grievance procedure to deal with complaints of misconduct at Westminster.

The move comes amid intense speculation that other MPs have been involved in inappropriate behaviour towards women in the wake of the allegations about disgraced Hollywood movie mogul Harvey Weinstein.

The decision to investigate Mr Garnier was disclosed by Health Secretary Jeremy Hunt during a television interview on BBC1's The Andrew Marr Show.

"These stories, if they are true, are obviously totally unacceptable," he said.

A Conservative Party spokesman said: "As the Prime Minister has made clear, any reports of sexual harassment are deeply concerning and any unwanted sexual behaviour is completely unacceptable in any walk of life, including politics.

"The Prime Minister is writing to the Speaker of the House of Commons calling for a new contractually binding grievance procedure to be set up for all MPs and their staff.

"Today, as a result of allegations about a serving minister, the Prime Minister has also asked the Cabinet Office to conduct an immediate investigation to see whether those reported actions break the ministerial code."

Mr Garnier's former secretary Caroline Edmondson told The Mail on Sunday that the married MP had given her the money to buy two vibrators at a Soho sex shop.

Ms Edmondson, who has since left to work for another MP, said that on another occasion, in front of witnesses, he called her "sugar tits".

The Mail said Mr Garnier had admitted the claims, saying: "I'm not going to deny it, because I'm not going to be dishonest. I'm going to have to take it on the chin."

According to the paper, he said the "sugar tits" comment was part of an "amusing conversation" about the TV comedy Gavin And Stacey, while the sex toys were bought after a Christmas lunch.

"The vibrator shop was high jinks. I hung around outside and she went into this shop. That was it," he is quoted as saying.

The Mail said Mr Garnier had conceded that, in the current climate, his actions could look like "dinosaur behaviour", but insisted: "It absolutely does not constitute harassment."

In a separate case the Mail said former cabinet minister Stephen Crabb had admitted sending "explicit" messages to a 19-year-old woman he interviewed for a job in 2013, when he was a Welsh minister.

The married MP was quoted by the paper as saying he had been "foolish" but that there had been no sexual contact.

"We exchanged messages which talked about sex but none of it was meant seriously," he was quoted as saying.

"We met for coffee a few times and had a glass of wine once at the Commons, but nothing more.

"I accept any kind of sexual chatter like this is totally wrong and I am sorry for my actions."

Mr Crabb resigned last year as Work and Pensions Secretary following reports of a similar incident.

Former Tory opposition whip Owen Paterson said if there was an allegation of a legal offence the Whips' Office should take it further.

He told Sunday with Paterson on Sky News: "I think it depends on the severity of the offence or the activity - in some cases, some of these recently reported activities, obviously totally inappropriate but the individuals concerned have apologised.

"But there might be, for all I know, offences which are more serious in which case perhaps the Whips' Office should take it further."

The former cabinet minister added: "It is obviously incumbent on Members of Parliament to behave properly but, as I said, there are certain areas where I think an admission of guilt and a full public apology is right, but if the whips are privy to much more serious allegations where an actual legal offence might have been called, perhaps they then have to take it further."