Boris Johnson's special adviser for civil society and communities' plans to quit the government in May were announced as ministers sought to defend a controversial report into racial disparities.
Samuel Kasumu reportedly told colleagues of his plans to quit just hours before the government released a landmark race report which concluded there was no evidence of "institutional" racism in the UK.
His resignation, reported by Politico, came as ministers battled to defend the report from accusations it had "glorified" the slave trade.
But Downing Street sources strongly disputed any link between his decision and the publication of the report, pointing to his decision to remain working on the vaccination programme until May.
It comes after the BBC reported that Kasumu had written to the prime minister in February to offer his resignation, saying the Conservative Party were pursuing "a politics steeped in division", before withdrawing his decision after conversations with vaccine minister Nadhim Zahawi.
But a source told Politico that Kasumu felt "physically and mentally exhausted" following his work on the Windrush scandal review, the race review and the vaccine campaign.
His resignation comes as the government battles to defend the report, which has been heavily criticised by racial equality activists, including for a comment which called for a "new story" about slavery to be taught in schools.
Speaking on Thursday, universities minister Gillian Keegan, said: "It doesn't glorify the slave trade. It is an independent report and obviously we have the report as of 11am yesterday and we will be looking at it.
"It did recognise the inhumanity of slavery, it did make many recommendations about how we educate and teach young people about slavery."
She added: "They look at disparities, they look at equality. They do say there is racism. There is a lot of criticism in the report, there are a lot of recommendations in the report as well...
"The report has recognised all of these things, so I think it is a very detailed report. The ten commissioners have spent a lot of time, a lot of effort, spoken to thousands of people, and I think the minimum we can do is take the report seriously, read it, and look at the recommendations and respond to it."
Meanwhile, asked about Kasumu's resignation, she said she "didn't know who he was" before adding his decision was a personal matter.
Comms tactics "enough to make a cynic of anyone"
The government attracted criticism not only for the content of the report, but also for the way its content was communicated.
Before the report was published in full, selected sections of the 258-page report were published, driving media coverage of its findings.
Will Molloy, chief executive of the charity Full Fact, said the approach was "harmful" and impeded people's ability to understand or scrutinise the report's recommendations.
"The topic of race in Britain is too important and sensitive to treat in this way," he wrote.
"These tactics are enough to make a cynic of anyone – and sadly and damagingly almost everyone is a cynic already when it comes to what politicians say."
He said the tactics were a symptom of a series of changes that had happened in recent years to make government communications less transparent, which also included private lobby briefings, targeted adverts and the prime minister's "people's question time", which have the appearance of transparency while answering only curated softball questions in pre-recorded videos.
"The Government Communications Service, part of the civil service, should serve all of us. At its best it does and the lifesaving importance of good public information during the pandemic proves how vital it is that public trust is not squandered by tactics like these," wrote.
Recommendations to "improve lives and experiences"
The report made a wide-ranging set of recommendations on how to “improve the lives and experiences of individuals and communities across the UK”.
They are split up according to four overarching aims, and cover policing, health, education and employment, as well as the language used to discuss such issues.
The aims are: “To build trust between different communities and the institutions that serve them, to promote greater fairness to improve opportunities and outcomes for individuals and communities, to create agency so individuals can take greater control of the decisions that impact their lives, and to achieve genuine inclusivity to ensure all groups feel a part of UK society.”
On building trust, the report's authors say more must be done to “challenge racist and discriminatory actions”, and call on the Equality and Human Rights Commission to receive “additional, ring-fenced funding from the government to use their compliance, enforcement and litigation powers to challenge policies or practices that either cause significant and unjust racial disadvantage, or arise from racial discrimination”.
To promote fairness, the report calls for the government to “deploy additional funding to systematically target the entrenched and persistent disparities in education outcomes between disadvantaged pupils and their peers”.
And among other things, the report recommended that the government establish a new office to properly target health disparities in the UK, working independently alongside the NHS, and as most causes of health inequalities are not due to differences in healthcare, it needs to work across multiple government departments.
John Johnston is a reporter and Alain Tolhurst is chief reporter for CSW's sister title PoliticsHome, where this reporting first appeared.