Britain’s interior ministry on Monday began the first public testing of the registration system for all EU citizens who hold a valid passport and any non-EU citizen family members who hold a valid biometric residence card. Research group British Future said the scheme could harm vulnerable groups such as the elderly and people with limited English or computer skills, and warned of a new Windrush scandal unless the government addressed its shortcomings.

Britain is home to about 3.5 million EU nationals and many of those will need to apply for inclusion on a new “settled status” register before July 2021 if they want to stay.