Making migrants pay a 'health surcharge' as part of their visa application could cost the NHS more in the long run the government has been warned.
Government plans would see migrants from outside the European Economic Area (EEA) coming to the UK for longer than six months is now required to pay a £200-a-year fee.
The Department of Health said the move would ensure those coming into the UK make an "appropriate financial contribution to the cost of the health services they may use".
Writing in the BMJ, Lilana Keith of the Platform for International Cooperation on Undocumented Migrants in Brussels, and Ewout van Ginneken, a senior researcher at Berlin University of Technology, said that the Government wants the public to believe the country will become less appealing to undocumented migrants and will save taxpayers' money, but "this view is shortsighted and misleading".
The report claims that denying those that have not paid the surcharge access could cost more, as emergency services, which must be provided at the point of need, are far more expensive than preventive or planned care and the NHS can rarely recoup these costs from patients who do not have the means to pay.
They said that the estimated 618,000 undocumented migrants living in the UK - who would not have paid the surcharge - contribute to the economy through their employment, from buying goods and services, and may even pay or have paid income tax.
They said that not having access to preventive services could also lead to outbreaks of infection or disease at a far greater cost to the health system and wider society. Thirdly, evidence shows that undocumented migrants are healthier, cost less to cover, and use services they are entitled to less than nationals, they said, citing examples of Sweden and Spain as recently finding this. Finally, they said the administration of charging migrants is in itself a major burden on the NHS.
The pair quoted a recent Doctors of the World report, which found that only 2.6% of respondents cited health problems as a reason for migration.
The new measures were implemented in April, as part of plans which the Government said will help recoup up to £500 million a year by the NHS by 2017/18.
They see patients being asked questions about their residence status in the UK whenever accessing a new course of treatment, and if there is uncertainty about their residence status, they may be required to submit documentation including passports and immigration documents. Hospitals receive an extra 25% on top of the cost of every procedure they perform for an EEA migrant or visitor with a European Health Insurance Card (EHIC), while short-term visitors from outside Europe will be charged 150% of the cost of treatment.
The Department of Health also previously said it is looking at piloting ways the NHS could recover costs from international visitors seeing GPs.