Boris Johnson’s comments about women wearing the burka gave the impression that the Tories were “insensitive to Muslim communities”, an independent review into allegations of Islamophobia in the Conservative party has found.

In a pointed message to the prime minister, the review led by Professor Swaran Singh said the leadership of the Conservative Party “ought to set a good example for appropriate behaviours and language”.

“Several” witnesses told Prof Singh’s investigation that they found Mr Johnson’s language “discriminatory and unacceptable”, the report said.

And one witness told the inquiry that the comments led to “a large increase in anti-Muslim events” reported to the Tell MAMA project, which records incidents of Islamophobia hate.

Mr Johnson sparked fury in 2018 with a newspaper column in which he said that he felt “fully entitled” to expect women to remove face coverings when talking to him at his MP surgery – and schools and universities should be able to take the same approach if a student “turns up… looking like a bank robber”.

Writing shortly after his resignation as foreign secretary, Mr Johnson said it was “weird and bullying” to expect women to cover their faces, adding:  “I would go further and say that it is absolutely ridiculous that people should choose to go around looking like letter boxes.”

In interviews during the 2019 general election campaign he said he was “sorry for any offence I have caused” but refused to apologise for the article, which he insisted was not written with the intent to offend.

Today’s report reveals that he refused to go beyond this form of words when responding to Prof Singh’s inquiry, but said that he would not repeat the remarks as prime minister.

Prof Singh said it was not within the remit of his inquiry to decide whether the PM’s comments breached the Conservative Party’s code of conduct.

But he added: “The investigation noted that several interviewees considered Mr Johnson’s language as discriminatory and unacceptable.

“Mr Johnson declined to add anything to his previously expressed regret that offence had been taken at his comments. He asserted that he would not make such remarks now that he was prime minister.

“While this could be considered leading by example, the investigation would like to emphasise that using measured and appropriate language should not be a requirement solely for senior people, but ought to be expected throughout the Conservative Party. “