Rupert Lowe, leader of the political group Restore Britain, faced criticism after declining to clarify whether he considers King Charles a white Briton during an interview on BBC Radio 4’s Today programme. This hesitation stems from Restore Britain's use of a definition of "white Briton" that excludes individuals with parents born outside the United Kingdom. Since King Charles's father was born in Greece, this definition excludes the monarch, as well as historical figures like Winston Churchill, whose father was also foreign-born.

Restore Britain’s position on race and nationality has generated controversy amid accusations that the group promotes a vision rooted in ethnonationalism. Charlie Downes, the party’s campaign director and co-founder, has been particularly controversial. He posted an image on social media suggesting that Nigel Farage had been influenced by British Jews, an act widely interpreted as invoking anti-Semitic tropes. Downes has also commented that the UK’s identity is based on “indigenous British ancestry and Christian faith,” statements that have further fueled concern over the party’s rhetoric.

Downes additionally launched a harsh personal attack on Allister Heath, editor of the Sunday Telegraph, after Heath criticized Restore Britain’s stance in an opinion piece. The party has not distanced itself from these remarks, and Lowe has not condemned or taken action against Downes, which has drawn further condemnation.

Critics argue that Restore Britain’s rhetoric promotes racial exclusivity and undermines efforts toward building an inclusive and multi-ethnic society. While some voices on the political right have expressed concerns about mass migration policies, calls for a mono-ethnic Britain are widely viewed as racist and counterproductive to national unity.

The controversy has raised warnings against alliances or cooperation between Restore Britain and other political figures such as Nigel Farage or Kemi Badenoch. Observers caution that any such cooperation could damage both political credibility and moral standing, reinforcing the perception that Restore Britain’s platform is incompatible with mainstream British politics.