The 24-hour nationwide strike has mainly affected major cities, with rallies scheduled in the likes of Athens, Thessaloniki and Chania.

The strike is going ahead, though, without the country’s air traffic controllers. The union representing ATCs confirmed a court had ruled its members’ participation in the 24-hour walkout had been deemed illegal.

The decision was welcomed by carriers such as Jet2.com which said all its flights to and from the country were now due to depart on time.

Nevertheless, the industrial action could still pose some issues for travellers, as metro services to and from Athens airport are not available on Thursday.

"A general strike has been called in Greece for Thursday 21 September (00:01 – 24:00)," said the FCDO in an update to its travel advice issued on Wednesday (20 September).

"Ferries may be affected and many airports may closed. Check with your transport provider if you are planning to travel by sea or air on 21 September. Buses and metro services may also be affected.

“Avoid demonstrations wherever possible and follow the advice of the local authorities."