BORIS Johnson's comments on Muslim women wearing the burka have been branded "inflammatory and divisive" by the Equality and Human Rights Commission.

The watchdog said he risked “dehumanising and vilifying” Muslims after he said those who wear face veils look like “bank robbers” and “letter boxes” – sparking accusations of Islamophobia.

It comes as Mr Johnson received unexpected support from Blackadder star Rowan Atkinson, who insisted he should not apologise for the remarks because they were a “pretty good” joke.

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Meanwhile, the Conservative Party's announcement on Thursday that Mr Johnson will face an inquiry has provoked a furious war of words, with many Tories regarding the move as an over-reaction.

Prime Minister Theresa May has called on him to say sorry, but former chief whip Andrew Mitchell said there was no need for the former foreign secretary to apologise for his "colourful" language.

In a letter to The Times, Mr Atkinson – one of Britain’s best-loved comedians – threw his weight behind Mr Johnson.

He wrote: “As a lifelong beneficiary of the freedom to make jokes about religion, I do think that Boris Johnson’s joke about wearers of the burka resembling letter boxes is a pretty good one.

“An almost perfect visual simile and a joke that, whether Mr Johnson apologises or not, will stay in the public consciousness for some time to come.

“All jokes about religion cause offence, so it’s pointless apologising for them. You should really only apologise for a bad joke. On that basis, no apology is required.”

The Mr Bean star has previously campaigned for the right to mock religion.

Rebecca Hilsenrath, chief executive of the Equality and Human Rights Commission, said the effectiveness of a democratic society depends on freedom of expression and “the expression of offensive and intolerant opinions is generally not unlawful”.

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But she added: "Boris Johnson's use of language in this instance, which risks dehumanising and vilifying Muslim women, is inflammatory and divisive.

"Political figures should lead by example, conducting debates in a responsible manner and language such as this can inhibit legitimate dialogue.

"The Conservative party has decided to conduct an investigation and will consider whether further action is necessary."

Mr Johnson, who is holidaying abroad, has so far made no response to the launch of the Tory investigation.

Disciplinary action could lead to him being suspended or even expelled, but would risk igniting civil war – with many MPs seeing him as a future leader.

The Uxbridge and South Ruislip MP made the controversial remarks in his Daily Telegraph column earlier this week, and has so far refused to back down.

He wrote that he did not support Denmark’s recent ban on face veils in public, but mocked the wearing of burkas.

First Minister Nicola Sturgeon accused him of "Islamophobia" and "dog whistle politics".

Scottish Tory leader Ruth Davidson backed calls for him to apologise, branding the comments "gratuitously offensive".

She said: "I think that this wasn't an off-the-cuff slip, he wrote a column, he knew exactly what he was doing and I think it crossed from being provocative and starting a debate and actually it became rude and gratuitous."

It comes as a YouGov poll for The Times found the Tories are now four points ahead of Labour, despite the row over Mr Johnson’s comments.

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The survey found 39 per cent of the public would vote Tory, an increase of one point on the previous week when both parties were level.

Labour, which has faced continued pressure over its handling of antisemitism in the party, fell three points to 35%.

Theresa May was 14 points ahead of Jeremy Corbyn, up seven points on last week, on the question of who would make the best prime minister.