Former UK foreign secretary Boris Johnson has been told to apologise after writing that the burqa, the Muslim garment that conceals a woman’s face and body, made wearers look like bank robbers and letter boxes.

Johnson used his weekly column in the Telegraph newspaper on Monday to argue against a ban on the burqa, as implemented by Denmark, France and Austria, saying people should be free to choose their own dress. But he mocked the clothing, saying it was "weird and bullying to expect women to cover their faces."

Conservative Party chair Brandon Lewis said on Tuesday that he had asked Johnson to apologise, though did not say if there would be any sanctions if the request were ignored. Johnson’s office did not immediately respond to a request for comment.

Since he resigned in protest at Theresa May’s Brexit plans in July, Johnson has been touted as a potential prime minister by those in the Conservative Party who want a harder departure from the EU. But others see his comments as an example of why he would be a poor candidate. Foreign office minister Alistair Burt said they were "offensive" and former Tory chair Sayeeda Warsi said they were "crass".

"Boris knew what he was doing," Warsi told Sky News. "Boris is making yet another leadership bid and he will say and do whatever needs to be said and done. I sincerely hope he doesn’t continue to use Muslim women as a convenient political football."