The UK's "extreme and secretive" citizenship-stripping powers are putting millions of British Muslims at risk of being deprived of their nationality, a new report has warned.

Research published by the Runnymede Trust and Reprieve on Thursday found that nine million people in the UK – approximately 13 per cent of the population – could be legally stripped of their citizenship at the home secretary’s discretion.

The powers, campaigners warn, disproportionately impact and endanger citizens with heritage linked to South Asia, the Middle East and Africa.

Both organisations warn that the "deprivation regime" now represents a systematic threat to Muslim communities, echoing the state’s discrimination against British nationals with familial links to the Caribbean in the Windrush scandal.

Under current law, British citizens can lose their nationality if the government believes they are eligible for another citizenship, even if they have never lived in that country or do not identify with it.