Boris Johnson’s adviser on ethnic minorities retracts resignation letter

The BBC said he wrote: “I fear for what may become of the party in the future by choosing to pursue a politics steeped in division.”

He said “the damage that is often caused by our actions is not much considered”, adding: “As someone that has spent his whole adult life serving others, that tension has been at times unbearable.”

The BBC said he also described the actions of equalities minister Kemi Badenoch, who launched an online tirade against a journalist last week, as “concerning”.

Badenoch accused HuffPost reporter Nadine White of “creepy and bizarre” behaviour and published correspondence between the reporter and officials on Twitter.

Kasumu is said to have suggested Badenoch may have broken the ministerial code – which the BBC said the Cabinet Office was looking into.

However, No 10 said during a Westminster briefing that there is “no Cabinet Office investigation ongoing”.

In his resignation letter, Kasumu wrote that “more concerning than the act, was the lack of response internally”.

“It was not OK or justifiable, but somehow nothing was said. I waited, and waited, for something from the senior leadership team to even point to an expected standard, but it did not materialise.”

A Downing Street spokesman said: “It would not be appropriate to comment on individual staff members.

“This government is committed to inclusion and bringing communities together, and is the most ethnically diverse in this country’s history.

“Last year we established a commission on race and ethnic disparities to examine and tackle inequality and discrimination wherever it is found. It is due to report shortly.”