The number of British visas granted to foreign health and care workers and family members of international students fell sharply after the previous Conservative government imposed restrictions to reduce net migration.

High levels of legal migration have long dominated Britain’s political discourse and were one of the major drivers for the Brexit referendum in 2016.

Former Prime Minister Rishi Sunak last year sought to reduce the number of foreign care staff and students coming to Britain, including preventing some post-graduate students from bringing family members.

Britain granted 89,095 health and care worker visas in the year ending in June, down 26% compared with a year earlier. Between April and June, the number of granted visas for these workers was down 81% year-on-year.

As part of efforts to bring down net immigration, the previous government tightened visa rules, introducing higher salary thresholds and curbs on care workers bringing in family members.

Marley Morris, associate director for migration, trade and communities at the Institute for Public Policy Research think tank, said the restrictions could exacerbate problems in a sector struggling to fill vacancies.

“The social care sector is still struggling with recruitment and the government will need to monitor the situation closely to avoid a further staffing crisis,” he said.

The total number of visas issued to foreign students to study at British universities was 432,225 in the year ending in June, down 13% compared with a year earlier.

While visas granted to dependants of overseas students in the first six months of this year fell by 81% to 11,675 compared to the same period a year earlier.

Britain boasts some of the most famous and sought after universities in the world, from Oxford and Cambridge to Imperial College London. Business leaders argue they boost innovation, increase creativity and provide a form of soft power.

But some British ministers in the last government complained that some students and their dependants were applying for visas and then claim asylum or overstay.

Polls show that controlling immigration is now the most important issue for British voters for the first time in eight years, following far-right riots targeting Muslims and migrants that began earlier this month.