Boris Johnson is to be investigated by the Conservative party for breaching their code of conduct, following his comments about Muslim women who wear burqas.

The former foreign secretary compared women who wear the items to "letter boxes" and bank robbers.

Investigators will consider whether Johnson should be disciplined following a deluge of complaints against him.

Johnson has so far refused requests to apologise for the comments.

LONDON — Boris Johnson is to be placed under an official investigation by the Conservative party following a deluge of public complaints about his comments comparing Muslim women who wear burqas to "letter boxes" and bank robbers.

The former foreign secretary will be investigated over whether he has broken the party's code of conduct for comments that were widely criticised by figures, including from his own party, as Islamophobic.

Sources told the Evening Standard that officials were now sifting through a "considerable volume" of public complaints about Johnson's comments.

The complaints will be assessed by an independent investigator before potentially being passed to a full panel appointed by the Conservative party Chairman Brandon Lewis and the Chair of the 1992 backbench committee of Conservative MPs.

Under Conservative party rules, MPs must adhere to "minimum standards of behaviour" under the code of conduct and "lead by example to encourage and foster respect and tolerance."

Johnson, who is on holiday, has so far resisted pressure from Lewis, numerous MPs, and the Prime Minister Theresa May herself, to apologise for his comments and has as yet to speak publicly about the claims.

However, a source close to Johnson described the decision to launch an investigation into him as "mad"

"The world has gone mad. Or specifically the people at Matthew Parker Street (Conservative Central Office) have gone mad," the source told Sky News.

"They and Number 10 would be very, very wise to calm this down very, very quickly."

The investigation was welcomed by the Conservative former co-chair and current peer Baroness Warsi.

"Boris is merely a symptom, the disease of Islamophobia runs far deeper," Warsi tweeted.

"I welcome this investigation into Boris but let’s not pretend this is an isolated incident.We must have an independent enquiry which includes all that have indulged in anti Muslim rhetoric."