BORIS Johnson should "do the grown up thing and apologise", the city's MP has said.

Worcester MP Robin Walker said the former Foreign Secretary made a "silly remark" when comparing Muslim women in burkha's to "letter boxes" and "bank robbers" on Monday - a comment for which Mr Johnson will now be the subject of a disciplinary investigation by the Tory party.

Mr Walker said: "I think he made a silly remark and he should apologise for the offence he has caused.

"The Prime Minister came out publicly and thought he should apologise and I completely agree with her.

"He is a backbencher now so he is not part of the Government. What he said is a personal remark and the way that should be dealt with is by coming out and apologising."

Mr Walker said given Mr Johnson's previous role as Foreign Secretary, he "should have known better."

Despite calling Mr Johnson's comments "unnecessary", Mr Walker said he agreed with the view explored in his article on Monday (August 6) which said the government should not ban the burkha.

"With the debate about the burkha, I think he is on the right side," said Mr Walker.

"I don't think we should be banning the burkha.

"You can't ridicule somebody for how they choose to dress, particularly if the way they choose to dress is for religious reasons.

"People should be able to make their own choices without the fear of being ridiculed. It was completely unnecessary and something he should apologise for.

"I expect him to do the grown up thing and apologise."

Mr Walker did not know why Mr Johnson made the remarks and disagreed his comments were pandering to the far-right.

"No, I don't think so," he said.

"If he was talking about complete banning the burkha then maybe I could say he was but I don't think he is.

"Having said that I do also think that it is important that we have free speech in this country."

Mr Johnson has faced a wave of criticism throughout the week for his remarks and has so far refused to apologise.

Conservative peer Baroness Warsi accused Mr Johnson of making "hate crime more likely" whilst Prime Minister Theresa May said it was "wrong" to use such language and urged him to apologise.