International Trade minister Mark Garnier will be investigated over a possible breach of ministerial rules after he admitted asking a former aide to buy sex toys.
The Cabinet Office will probe whether the Wyre Forest MP broke the Ministerial Code after he confirmed allegations made by his former secretary, including that he called her sugar t***.
Health Secretary Jeremy Hunt confirmed the investigation on BBC One’s Andrew Marr Show.
The Prime Minister will also write to House of Commons Speaker John Bercow to ask how a sexual harassment scandal engulfing Westminster can best be addressed.
It comes as Theresa May was reported to get weekly updates about indiscretions by her MPs from Conservative Party whips, leading to calls for allegations to be reported to police.
Meanwhile, former Cabinet minister Stephen Crabb admitted to being foolish by sending messages which talked about sex to a 19-year-old woman he interviewed for a job.
The Westminster scandal broke following the revelation female staff in Parliament use a WhatsApp group to warn each other about male MPs and other senior figures from across political parties.
Downing Street said Mrs May found those claims “deeply concerning”and would take any allegations “extremely seriously”.
Married father-of-three Mr Garnier told the Mail on Sunday he did not contest the claims against him and conceded it could “look like dinosaur behaviour”, but strongly denied sexual harassment.
I’m not going to deny it, because I’m not going to be dishonest, he said.
I’m going to have to take this on the chin.
The former investment banker claimed his reference to ex-aide Caroline Edmondson as sugar t*** was part of an amusing conversation based on TV comedy Gavin & Stacey, which uses the phrase.
He also described asking married Ms Edmondson to buy sex toys as good-humoured high jinks after a Christmas lunch, with Mr Garnier claiming he told her he didn’t think it was a good idea.
Ms Edmondson, who stopped working for the Wyre Forest MP shortly after the incidents in 2010, disputed Mr Garnier’s version of events, telling the newspaper: He has lied.
The MP described Ms Edmondson as a disgruntled former employee.
Mr Crabb, who stood for the Conservative leadership last year, also confirmed to the Mail on Sunday he sent messages to a young woman he interviewed for a job in 2013.
Stephen Crabb The Preseli Pembrokeshire MP told the newspaper: We exchanged messages which talked about sex but none of it was meant seriously.
We met for coffee 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.
The incident was reported to have happened before Mr Crabb resigned from Cabinet in July 2016 citing family reasons.
It followed separate allegations he sent suggestive text messages to a young woman.
The scandal engulfing Westminster, which follows claims against movie mogul Harvey Weinstein that rocked Hollywood, has also seen allegations made against unnamed figures from other parties.
A Labour MP is reportedly known as “Happy Hands” while a Liberal Democrat peer is said to invite female journalists to lunch on the insistence they wear short skirts, according to the Sunday Times.
Downing Street is said to be fearing the scandal could prompt an emergency Cabinet reshuffle – amid claims it could also involve senior ministers – destabilising the Government and even threatening Mrs May’s position.
Westminster On Saturday, Environment Secretary Michael Gove apologised after sparking outrage by making a joke about sexual assault on BBC radio. Sky News has attempted to contact both Mr Garnier and Mr Crabb.
A Conservative 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.