The Remain camp has questioned the £350 million a week figure cited by the Leave camp, noting that the figure is inaccurate because the UK receives an upfront refund for its economic contributions to the EU, meaning the UK actually spends £250 million a week.

The independent UK Statistics Authority has also called the claim “misleading” as it did not take account of the refund received by Britain or other payments the EU makes to help the public and private sector in the UK.

The Remain camp argues that leaving the EU would result in less money coming into the economy and therefore less money being invested in the NHS.

They argue that withdrawing from the EU would result in British holidaymakers and ex-pats having to pay for their healthcare – they would lose their access to free emergency healthcare in the EU and automatic entitlement to a European Health Insurance Card, which provides access to free or discounted medical care in all EU member countries.

They believe the number of trained doctors and nurses working in the NHS could drop sharply if Britain leaves the EU. Thousands of current NHS workers come from the EU, with 14% of the NHS clinically qualified staff and 26% doctors being foreign nationals.

The Leave camp believes leaving the EU would free up the current £350 million a week membership fees currently being sent to the EU to be invested in the provision of more staffed hospitals.

They believe EU rules have weakened doctors’ safety checks, making patients less safe, and have held back the advancement of cancer research.

They claim that the EU is taking more control of the NHS, forcing more privatisation and only by leaving will there be a halt to this creeping privatisation of the NHS.

They argue that the UK would be able to close the £5.78 billion payment gap between what it pays to other EU member states for the treatment of British citizens in the EU and what it is able to recoup from EU countries for the cost of treating EU citizens in the UK.

They state remaining in the EU would lead to greater pressure on the NHS from having to treat EU migrants. The campaign cites the illustrative example of the 475,000 live births to mothers from other EU countries between 2005-14 which, it claims, could lead to treatment costs of £1.33 billion.

They argue that the free movement rules in the EU have meant that it has not been possible to test the English language proficiency of doctors with “tragic and fatal consequences”.

Each individual EU country has its own different health system, so in one sense the UK leaving the EU would not change much about the NHS. On the crucial point about whether the NHS spends more on treating EU nationals than other EU countries spend on treating British citizens, it appears that the sums are roughly equal. This can partly be explained by the relatively large amount that other EU member states – particularly Spain – spend on medical care for British pensioners who live abroad.  

Were Britain to leave the EU, it is likely that the UK and remaining Member States would reach some sort of deal on emergency care that covered tourists at the very least. Negotiations on a broader deal covering retirees, students and workers from the UK in the EU and from the EU in the UK respectively may take longer and be more difficult.