UK Prime Minister Theresa May and Conservative Party Chairman Brandon Lewis criticized former top diplomat Boris Johnson on Tuesday for disparaging comments he made about Muslim women wearing burqas.

May said she agreed with the Conservative party chairman, Brandon Lewis, that Johnson should say sorry for resembling burqa wearing Muslim women to letterboxes and bank robbers.

"Some of the terms that Boris [Johnson] used in describing people's appearance obviously have offended people…," May 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," May told reporters following a meeting with Scottish First Minister Nicola Sturgeon.

May underlined that she is "very clear and the government is very clear about our position on the issue of the burqa, which is that women should be able to choose how to dress."

"It's up to a woman to decide how to dress, it's not up to other people to tell a woman how to dress," she added.

The premier also said discussions "about issues like this, but in doing that we all have to be very careful about the language and the terms that we use."

Johnson has come under fire after his offensive remarks with many MPs, NGOs, Muslim organizations and councils denouncing them.

The Muslim Council of Britain (MCB) has also called on the Conservative party to respond to serious concerns of Islamophobia.

"Today the Muslim Council of Britain calls on the Conservatives to respond to serious concerns of Islamophobia in the party, especially after Boris Johnson made unacceptable remarks comparing Muslim women who wear the niqab to letterboxes and bank robbers," a statement from the MCB read.

The MCB also said that while it was right for party chairman to call on Johnson to apologize, the party should now act upon calls that had been previously ignored.

The Muslim Council of Britain (MCB) wrote two letters to the Conservatives this year urgently calling for an inquiry, as have groups such as the National Union of Students, the Union of Jewish Students, and institutions representing over 200 mosques in the U.K.

Writing in the Daily Telegraph on Monday, Britain's one-time top diplomat described the burqa as "ridiculous" and "weird" and said women wearing them looked like "letter-boxes" or "bank robbers."

Johnson, who resigned as foreign secretary in July over Prime Minister Theresa May's Brexit strategy, was swiftly condemned by former colleagues and fellow lawmakers.

Foreign Office Minister Alistair Burt told the BBC: "I would never have made such a comment, I think there is a degree of offense in that, absolutely right."

Tory peer Sayeeda Hussain Warsi, a former party chair and diplomat, accused Johnson of adopting the "dog-whistle" tactics of right-wing firebrand Steve Bannon, U.S. President Donald Trump's former top aide.

Johnson has been in direct communication with Bannon in recent months, according to reports last month.

Warsi said Johnson was hoping to attract support from right-wing Conservatives for an eventual leadership bid, and called for an independent inquiry into Islamophobia in the party.

"Muslim women should not be a useful political battleground for Old Etonians," she told Channel 4 News, referring to the private school popular with Britain's political elite.

"It is crass and it must stop, and it must be condemned by the leadership right from the prime minister down."

Johnson received support from some quarters amid the furore over his comments, with Tory MP Nadine Dorries saying he "did not go far enough."

"Any clothing a woman is forced to wear which hides both her beauty and her bruises should be banned and have no place in our liberal, progressive country," she said.

Meanwhile, Johnson's father, Stanley, told ITV's Good Morning Britain: "I think people are whipping up a little mountain out of a molehill on this one, I really do."