- Video report by ITV News Correspondent Angus Walker
Prime Minister Theresa May has piled pressure on Boris Johnson for his remarks around Muslim women wearing burkas as he continues to resist pressure to apologise.
The former foreign secretary has branded those criticising his comments "ridiculous."
Mrs May has said she agrees with Conservative Party chairman Brandon Lewis, who earlier called on Mr Johson to apologise for his controversial words.
"I do think that we all have to be very careful about the language and terms we use.
"And some of the terms Boris used describing people's appearance obviously have offended. So I agree with Brandon Lewis," she said.
"What's important is do we believe people should have the right to practise their religion and, in the case of women and the burka and niqab, to choose how they dress.
"I believe women should be able to choose how they dress."
A source close to Mr Johnson made it clear that he was not retracting his words.
"It is ridiculous that these views are being attacked - we must not fall into the trap of shutting down the debate on difficult issues," said the source.
"We have to call it out. If we fail to speak up for liberal values then we are simply yielding ground to reactionaries and extremists."
Brandon Lewis's call followed a hail of criticism for Mr Johnson’s remarks, which were described as “offensive” by Foreign Office minister Alistair Burt and “bigotry” by former Tory chair Baroness Warsi.
Writing in the Daily Telegraph on Monday, the former foreign secretary described the burka as “ridiculous” and “weird” and said women wearing them looked like letter-boxes or bank robbers.
While agreeing with Mr Johnson that the burka should not be banned, Mr Burt told BBC Radio 4’s Today programme: “I would never have made such a comment, I think there is a degree of offence in that, absolutely right.”
And Lady Warsi accused Mr Johnson of adopting the “dog whistle” tactics of former Donald Trump aide Steve Bannon in the hope of attracting support from right-wing Tories for an eventual leadership bid.
Repeating her call for an independent inquiry into Islamophobia in the Conservative Party, Lady Warsi told Channel 4 News: “Muslim women should not be a useful political battleground for Old Etonians.
“It is crass and it must stop, andit must be condemned by the leadership right from the Prime Minister down.”
In a message on Twitter, Mr Lewis said: “I agree with Alistair Burt. I have asked Boris Johnson to apologise.”