“We were trying to get people to understand racism as a white problem,” says Kate Webb, an early member of the Rock Against Racism movement, which emerged in 1976 in protest at the white supremacist attitudes of the then fast-growing National Front. The group’s idea to “peel away the union jack to reveal the swastika” feels eerily resonant more than 40 years later.

Rubika Shah’s smart, spirited feature debut is a whistle-stop tour of a DIY uprising. Her documentary collages archive footage of race riots in Notting Hill and Lewisham, with slickly annotated newspaper clippings, handwritten letters and excerpts from RAR fanzine Temporary Hoarding, inspired, perhaps, by its cut-and-paste aesthetic. Shah places these alongside contemporary interviews with the movement’s founders as well as some of the black artists involved, such as the Selecter’s Pauline Black and Mykaell Riley of Steel Pulse. It’s a world away from today’s social media activism and corporate-sponsored campaigns, but Shah seems energised by, rather than nostalgic for, a more grassroots anti-racist crusade.

Available on Modern Films, 24-28 June, and other dates this summer, before an autumn cinema release