The Herald has parted company with long-serving columnist Iain Macwhirter after he described ethnic minority MPs promoted to top jobs in the UK government as “the coconut cabinet”.

Mr Macwhirter, a former BBC political correspondent and one-time rector of Edinburgh University, sparked a social media backlash for posting the comment in a tweet responding to Liz Truss’s decision to appoint the first cabinet in history in which none of the great offices of state are held by white men.

The Glasgow-based newspaper group said that after investigating the incident it had “mutually agreed” that Iain will leave The Herald to pursue other opportunities. His final column will appear on Sunday.

In a statement on Twitter, The Herald said it was “satisfied there was no racist intent in what was still an offensive and unacceptable tweet by our freelance contributor Iain Macwhirter…

“Iain has been an exceptional long-serving political commentator for The Herald for over 22 years…

“He has written thoughtfully on race and other sensitive issues … and these pieces have always met our editorial standards and have been well-received by our readers.

“He goes with our best wishes and we want to put down our sincere thanks to him for the body of work he has achieved with the newspaper.”

The tweet appeared in a brief exchange of views on the new Cabinet. Kwasi Kwarteng, the son of Ghanian immigrants, is the new Chancellor. James Cleverly, whose mother was from Sierra Leone, was appointed Foreign Secretary, and Suella Braverman, whose mother was born in Mauritius, is Home Secretary.

Tim Bale, professor of politics at Queen Mary, University of London, tweeted: “Folk (including @BBCr4today) are (rightly!) celebrating diversity in the ‘great offices of state’. But it’s maybe worth noting Kwarteng, Cleverly, and Braverman were all privately educated. Fact is that, nowadays, the real lack of diversity in Parliament is class-based.”

Mr Macwhirter, who has continued to provide commentary to the BBC, responded: “The coconut cabinet?”

The term is regarded as a derogatory term which implies people of colour are white on the inside.

One respondent to Mr Macwhirter’s comment tweeted: “It’s 2022 and bold as brass you’re calling people coconuts on social media. Absolutely shameless racism, not even embarrassed — disgusting.”

Shirley Brown, a black Liberal Democrat councillor in Bristol, was convicted of racial harassment for describing Jay Jethwa, a black Conservative councillor, as a “coconut” in 2010.

Mr Macwhirter deleted his tweet and apologised. He said: “Earlier, I made an ironic reference to a term used by some on the left about black people who are deemed traitors to the cause through joining the Tory Party.

“After I posted it, I realised this joke might give offence and deleted it. It was unacceptable language, wide open to misinterpretation, and I am sincerely sorry for the distress I have caused.

“I have repeatedly applauded the Conservatives for having the most diverse cabinet in British history. Indeed, I tweeted earlier that the Truss cabinet made the Scottish government look ‘hideously white’.

“I have always championed racial diversity in my columns and I am dismayed that my cack-handed attempt at humour suggested otherwise.”

Macwhirter is a founder-member of the Free Speech Union Scotland, which was established to oppose the emergence of cancel culture.