In a statement, SEF said that checks on 1,737 UK nationals had taken place "without any constraints on border control".

The airport with the highest flow of British passengers was Faro with 688 passengers, followed by Lisbon (629), Madeira (240), Porto (177) and Tires (3), SEF said.

SEF points out that there is currently legislation in force authorising air traffic to and from Portugal for all flights to and from countries outside the European Union or countries associated with the Schengen area, such as the United Kingdom, exclusively for essential journeys (for professional reasons, study, family reunion, health or humanitarian reasons) or to allow nationals of third countries, including the United Kingdom, legally resident in Portugal, to enter or leave Portugal