Prime Minister Boris Johnson's new adviser Andrew Sabisky announced his resignation on Monday night after MPs lashed out at Tories for condoning his eugenics remarks.
A political scandal around Sabisky's appointment flared up after some of his past comments emerged.
In one of his 2014 posts, the now-former adviser suggested that black people on average have lower IQs than white people and proposed the government to rethink the immigration system, basing it on “very real racial differences in intelligence".
In another comment, Sabisky said that benefit claimants “tend to be less conscientious and agreeable” thus should be encouraged to have fewer children than people working with more “pro-social personalities”.
The resignation has dealt a heavy blow to Johnson's top aide Dominic Cummings, who was an active proponent of the idea of hiring "weirdos and misfits with odd skills" to work in Whitehall, inviting those who think they "fit one of these categories" to apply.