A holiday to France could cost a pensioner with common health problems hundreds of pounds in insurance following Brexit, MPs have heard.
If Britons lose their European Health Insurance Card (EHIC), older people with multiple conditions could be forced to fork out hundreds, if not thousands, for a week in France, the Health Select Committee was told.
When questioned on current reciprocal agreements on health care between EU member states, Martin McKee, professor of European public health at the London School of Hygiene and Tropical Medicine, said the insurance card has "many benefits".
Prof McKee said that he had searched for how much it would cost in insurance for someone to visit France for one week.
"The advantage of EHIC is that is covers pre-existing conditions so if you want to travel abroad as a British tourist and go to France, you are covered and vice versa.
So (in preparation for this hearing) I put in a few co-morbidities, like diabetes and a history of mild depression, to see how much it would cost for a one-week stay in France. It came out between £800 and £2,500. So I think that would have some impact on our tourism.
"I put in a 70-year-old with common conditions - and remember that with the rise of multi-morbidity most people over the age of 70 will have multiple conditions.
"It will mean effectively that they will not be able to travel, or at least they can travel but they would take a risk of something goes wrong."
He suggested that the insurance bill post-Brexit could be even greater.
A European Health Insurance Card gives travellers the right to access state-provided healthcare during a temporary stay in another European Economic Area (EEA) country or Switzerland.
But surgeon Joseph Meirion Thomas, a campaigner against health tourism, told the Committee that the UK pays out five times as much as it receives back from the EHIC scheme.
"I think the EHIC card has got to end with Brexit because the pendulum is heavily weighed against the UK," he told MPs.
"Anyone going from the UK to somewhere outside the European Union has got to have health insurance, what difference is it going to make if they have to [have health insurance if they] stay inside the European Union?
"So many people are buying it by the year anyway and it's a fairly reasonable cost."