If 48 per cent of migrant NHS nurses were no longer allowed to work in the UK under new immigration laws, this could have a “significant impact” on the quality of healthcare, the government has admitted.

According to the coalition’s own estimates, plans to prevent non-EU immigrants from staying in the UK from 2016 if they earn under £35,000 could take many hundreds of nurses out of the NHS.

“We estimate 48 per cent of migrant nurses, 37 per cent of primary school teachers, 35 per cent of IT/software professionals and 9 per cent of secondary teachers would be excluded,” the government’s impact assessment said.

The immigration minister Damian Green said: “For too long immigration was allowed to get out of control. Our radical reforms are ensuring that we are selective not just about who can come here but also who will be allowed to stay permanently. These changes represent real progress on our promise to bring immigration back to sensible, sustainable levels, and to bring in only those migrants who can make the greatest contribution to life in the UK.”

But Unison’s head of nursing Gail Adams commented: “The government should think again about these restrictions on overseas nurses. They have cut the number of nurse training places by 20 per cent over the last two years, which means we will not have enough qualified nurses to cover those coming up to retirement.

“These crude restrictions will make matters worse and create skill shortages in the future. The quality of care will obviously suffer if hospitals cannot recruit the nurses they need to ensure a safe ratio of nurses to patients.”