Hospitals will be required by law to check whether patients are eligible for free care on the NHS from April onwards, the health secretary has announced.

The rule raises the prospect of patients having to produce their passports and other identity documents before receiving most kinds of treatment as the government aims to claw back £500m a year. Patients from overseas will also be billed in advance for all non-urgent care as part of a government clampdown on the cost of overseas visitors using the service.

The Department of Health said nobody would be denied emergency treatment, whether they could pay or not. Under the changes, migrants from outside Europe, who pay an immigration health surcharge, will also lose their right to free NHS fertility treatment.

Jeremy Hunt said: “We have no problem with overseas visitors using our NHS – as long as they make a fair contribution, just as the British taxpayer does. So today we are announcing plans to change the law which means those who aren’t eligible for free care will be asked to pay upfront for non-urgent treatment.”

Doctors of the World, which runs clinics in the UK, raised concerns about the impact of identity checks. Shyamantha Asokan from the medical charity told “We see really vulnerable people: undocumented migrants, victims of human trafficking, homeless people. Already they’re often very worried about going to a hospital because they are worried about being asked for documents they don’t have or being asked to pay.”

She added: “A lot of the doctors who volunteer for us don’t want to be made into border guards – they just want to treat the people in front of them … We don’t believe that immigration and healthcare are areas of government policy that are overlapping.”

When a senior official acknowledged the government was considering introducing identity checks last November, some doctors threatened to boycott the scheme.

“If migrants know that doctors and other healthcare professionals will actively liaise with the Home Office to deport them then they will avoid seeking healthcare. That’s hugely dangerous – especially in pregnant women, because without prompt early access to healthcare they stand a much higher risk of presenting as an emergency later on, potentially with much worse outcomes.”

The Department for Health said refugees and asylum seekers were exempt from paying, and that hospitals would work with people who do not have the required documents to establish whether they are eligible. The government is “determined to ensure there is minimal burden on British citizens”, a press release said.

Health tourism, where people travel to Britain for NHS treatments they are not entitled to, takes up about 0.3% of the NHS’s budget, according to fact-checking website Full Fact. This could include British citizens living overseas who return to the UK for treatment. Treating people who fall ill while visiting the UK costs the NHS about £1.8bn a year.

A National Audit Office report last year said the government paid £674m to other European countries for treatment of Britons abroad, but received only £49m in return for NHS treatment of European citizens.

A pilot scheme for improving how much money is collected from patients who are not eligible for free care has been running in Peterborough and Stamford hospitals NHS foundation trust since May 2013. There, patients are told to bring a passport or birth certificate as well as proof of residence, such as utility bills or bank statements, to new appointments. The trust’s chief executive, Stephen Graves, said: “There has not been any impact on the number of non-UK residents coming through the system for treatment but we do now identify non-eligible patients sooner, and at a higher volume than previously.”

Here's To Your Health
We're reporting in on the latest in health news, medical research, insurance coverage, plus managing your health and the health of the people you love.
We respect your privacy