A leading thinktank for health has warned the National Health Service could be handed an annual bill of £1bn after Brexit.
The Nuffield Trust has said the high figure would come from the cost of treating British nationals living in the European Union.
At the moment, an EU scheme means the Department of Health pays £500 million to allow expats and pensioners abroad to have access to free or reduced healthcare across the 27 member-states.
The future of this arrangement is to be decided in the upcoming Brexit negotiations, but if it isn't protected, the Trust warns the sum paid by the NHS could double.
The main researcher, Mark Dayan, told The Independent the situation for the NHS could be further challenged if an economic slump occurs as a result of Britain's departure from the EU.
All mainstream parties have pledged to funnel money into the National Health Service, which faces an ongoing financial crisis.