Cabinet chief Gergely Gulyas confirmed the move in a press briefing late last week, with the decision coming into effect on Tuesday (1 September).

It means Hungary becomes the first country in the EU’s Schengen area to close its borders again to limit the spread of Covid-19. Much of the Schengen area reopened to intra-EU travel in late-June into early-July.

The border will remain closed for an initial one-month period.

Hungary’s decision is the most significant escalation of Covid protection measures in the EU, with several other countries having reimposed states of emergency or introduced stronger public protection policies such as tougher rules on face masks.

The UK currently has a quarantine-free travel corridor with Hungary, and the country is exempt from the Foreign Office’s global no-travel advisory.

However, the FCO has updated its advice to reflect Hungary’s plans to shut its borders.

"UK nationals will not be allowed to enter Hungary unless they hold a permanent residence permit or a permit allowing them to stay in Hungary for at least 90 days, and can present their documents to the authorities at the border," said the FCO.

"UK nationals travelling with a family member who is a Hungarian citizen or resident should also be allowed entry.

"UK nationals may also enter Hungary for the purposes of transit. Otherwise, entry is limited to narrow circumstances, such as operating cargo transport or travelling on a diplomatic or official passport.

"It is also possible to apply – before travelling - for an exemption to enter Hungary in a further set of specific circumstances, such as attending a funeral."

Hungary’s budget carrier Wizz Air said it expects second-quarter capacity to come in at "roughly 60%".

However, it said capacity could remain at 60% in its third-quarter, rather than returning to 80%, "if mobility restrictions across the network persist".

Wizz added further capacity reductions remain a possibility, which could result in it "parking parts of its fleet throughout the winter season to protect its cash balance".