Giving free coronavirus tests to holidaymakers who have not been vaccinated or had a second dose will cost up to €350m and there are many doubts about how to put the plan into practice, health minister Hugo de Jonge and infrastructure minister Cora van Nieuwenhuizen have told MPs.

MPs earlier voted in favour of picking up the bill for people who have not been fully vaccinated and who want to travel abroad this summer. The test will form part of the ‘coronavirus passport’ which the EU is currently developing.

One option would be to allow travel organisations to deal with the testing process and then to refund them, but this could conflict with EU rules on state support for industry. A second option would be to use regional health boards – even though their task is to ensure public health, not commercial testing.

‘The cabinet has concluded that carrying out the motion will bring with it legal risks and the possibility of fraud,’ ministers said. ‘Of course, the cabinet will do all it can to manage these, but cannot rule them out.’

The free test would only apply to the outward journey.