Plans to allow Britons to receive medical treatment anywhere in the EU must not raise "false expectations" for patients, an MEP has claimed.
Arlene McCarthy said the proposals, which are going before the Public Health Committee of the European Parliament, must not give people the impression healthcare in Europe is available "at any cost".
The move could mean all EU residents can be treated in other member states paid for by their country's health service, providing the care is allowed in their own country.
Ms McCarthy is the Labour chairman of the Internal Market and Consumer Protection Committee, which recently produced a report on health services in the EU.
She said: "The right to access healthcare in other EU countries must not undermine the integrity and financing of the NHS and it mustn't disadvantage those who don't have the cash to pay upfront for treatment."
Fellow Labour MEP Linda McAvan added: "Case law already exists from the European Court of Justice which allows patients who wish to receive care abroad to do so, and this has not resulted in a large number of people wanting to go abroad for treatment or a large number of other EU nationals seeking treatment in the UK.
"The priority for the vast majority of NHS patients is high-quality healthcare received close to their homes."