Boris Johnson and Lord Goldsmith are among the prominent Tories highlighted in Professor Swaran Singh’s report on alleged discrimination in the Conservative Party.

Here are some of the cases covered by the report:

Boris Johnson:

The Prime Minister was cleared by an independent panel, which examined whether he had breached the Conservative Party’s code of conduct by using a Daily Telegraph column in 2018 to describe Muslim women who wear the burka as looking like “letterboxes” and “bank robbers”.

But the panel looking at Mr Johnson’s case was split, with a minority view that the language used in the article was “offensive and did not lead by example to encourage and foster respect”, and that as a result Mr Johnson had breached the party’s code of conduct.

The Prime Minister told Prof Singh’s investigation: “I do know that offence has been taken at things I’ve said, that people expect a person in my position to get things right, but in journalism you need to use language freely. I am obviously sorry for any offence taken.

“Would I use some of the offending language from my past writings today? Now that I am Prime Minister, I would not.”

The report said that several interviewees who spoke to the investigation considered Mr Johnson’s language “discriminatory and unacceptable”.

In response to Mr Johnson’s assertion that he would not make such remarks now, the report said: “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.”

The panel’s findings in Mr Johnson’s case were made public, but not its deliberations, which led some of those interviewed by the Singh Investigation to consider it a “whitewash”.

The report said the case illustrates the need for complaints handling to be not only independent of the party structure but also for greater transparency about process and outcome on individual complaints, particularly those that might be considered “high profile”.

Lord Goldsmith of Richmond Park

The investigation examined the controversial and unsuccessful mayoral campaign run in London by Zac Goldsmith, as he was then, against Labour’s Sadiq Khan in 2016.

Lord Goldsmith said it was “important to hold Sadiq Khan to account for his record of associating with extremists, in particular Islamists”, but added: “I never believed that Sadiq himself was an extremist”, and his campaign had not suggested it.

But he acknowledged that the mayoral contest turned out to be “ugly and heavily racially charged” and “in hindsight it should have been obvious that the issue was too combustible to be discussed reasonably”.

Lord Goldsmith said: “On one side, there were anti-Muslim groups and individuals actively accusing Sadiq of being an extremist – a gross calumny.

“And on the other, Labour campaigners reframed legitimate questions about their candidate’s judgment in such a way that it appeared he was being smeared because of his faith… a large number of Muslim Londoners felt personally insulted by what they had been told was my campaign message, that is of course a source of major regret and sadness on my part.”

The report said Lord Goldsmith “accepts poor judgment in the way his campaign was conducted, but forcefully denies harbouring anti-Muslim sentiments or using such sentiments for political advantage”.

The mayoral campaign received one complaint, which was dismissed as unsubstantiated.

Bob Blackman

The Harrow East MP has been criticised in the past for hosting an event at which Tapan Ghosh, a Hindu nationalist speaker alleged to have made anti-Muslim remarks in India, appeared.

Mr Blackman described his role as an “arm’s length sponsor” for events hosted by the Hindu Forum of Britain and National Council of Hindu Temples, and he was not involved in the decision to invite Mr Ghosh, nor was he present during his speech at the event in Parliament.

The MP said he was “furious” with the National Council of Hindu Temples, publicly condemned the remarks attributed to Mr Ghosh and now conducts more due diligence on invited speakers.

The report said: “Mr Blackman acknowledges that hosting Mr Ghosh to Parliament without due diligence and knowledge of his social media posts were errors of judgment on his part, which he deeply regrets.”

In 2016, Mr Blackman retweeted a post by Tommy Robinson that contained a link to an article in one of the major Indian newspapers about Muslim violence against Hindus.

When questioned about this retweet, Mr Blackman said he was new to Twitter and he had not realised who had originally posted the story.

Mr Blackman said that all of the complaints discussed in the interview with the Singh Investigation had been put to the party chairman and had been dismissed.

The MP said he had frequently taken up issues affecting Muslim communities around the world and he did not consider himself to hold anti-Islamic views, “but I do think it is possible to criticise people who use their faith as a reason for bad behaviour”.

There does not appear to have been a formal complaint against Mr Blackman recorded by the Conservative Campaign Headquarters (CCHQ) team, the report said.