Passengers have been warned of possible flight disruption due to a threatened four-day strike at Tap Air Portugal after Christmas.
Twelve unions representing workers at the airline are considering industrial action between December 27-30.
Poor working conditions, and government plans to privatise Tap Air Portugal, were cited by union representatives as the reasons for the strikes. The airline employs more than 12,000 staff.
The carrier has been plagued by a succession of strikes resulting in the cancellation of more than 700 flights. It has reportedly lost around €25 million due to stoppages so far this year.
The scope of the upcoming festive season walk out, threatening travel chaos for thousands of passengers, will be unprecedented only comparable to a general strike staged in 1993.
The Foreign and Commonwealth Office said in an updated travel advisory that a “possible strike action by TAP Air Portugal staff on 27 to 30 December could cause disruption to flights. Check with the airline or your travel company for more information.”
Around 2.1 million Britons visit Portugal every year.