NHS England chief executive Simon Stevens warned yesterday that 130,000 Europe-born doctors, nurses and care workers could quit if Britain leaves the EU.

Mr Stevens argued that any pressure on the health service from migration is outweighed by the benefits of EU membership, and warned workers could walk away in the wake of a Brexit because of uncertainty over work visas.

He added that an economic slump could further hit the NHS’s bank balance, after trusts revealed the biggest ever deficit in the history of the health service last week.

“There’s a perfectly legitimate argument to be had on these topics but from the NHS’s perspective it is pretty clear that the balance of the advantage is such that the risks would be greater were we to find ourselves in economic downturn, were we to find a number of our nurses and doctors leaving,” he told the BBC’s Andrew Marr Show.

But former foreign secretary and Leave campaigner David Owen said the NHS was in a “very considerable mess” under Mr Stevens’ watch.

Lord Owen criticised the NHS in England for becoming a “marketised health service modelling itself on the United States” and pointed out his background with an US private healthcare firm.

“If there’s any danger to the NHS it is in staying in with all the elements of the NHS which are now involved with the EU,” he told the BBC’s Sunday Politics show.