More travel advisory notes for the EU were revised by the government on Wednesday, a day ahead of the introduction of the European digital certificate which should smooth travel between member states.

Denmark, Latvia and Sweden as well as Athens and Brussels have now all been classified as yellow zones, meaning people from the Netherlands will not have to go into quarantine or show a negative test certificate on their return.

The government is, however, urging everyone returning from abroad to take a voluntary coronavirus test on their arrival back, after a rise in infections thought to have been picked up in Spain and Portugal.

Mainland Spain remains an amber zone, which means all but essential journeys should be avoided. Britain too is amber.

The European digital certificate, which allows people to show officials they have either been fully vaccinated, recently recovered from coronavirus, or have a negative test result, is due to come into effect on Thursday.

The CoronaCheck app uses a QR code to show officials and airline staff that the person is cleared for travel between member states.

This means thousands of people in the Netherlands, who have only had one vaccine dose, are now trying to make appointments for the free coronavirus test promised by the government to ensure they can get away.

The pressure has led to problems on the phone lines and a spokesman for the health ministry has urged people not to try and book now if they plan a break in August.

Tests can be booked via testenvoorjereis.nl up to two weeks ahead of departure, although on Wednesday, only the phone lines were actually up and running. The free tests only apply to holidays within the EU.

Download the CoronaCheck app (in English) here.