Passengers in and out of Portugal might face delays, longer check-in times and might have to wait longer to reclaim baggage if proposed strikes by Portuguese airport workers go ahead.
Unions representing the workers are planning industrial action over three days from Friday, July 1.
British Airways is warning passengers to check in online and print boarding passes in order to free up queues.
A statement on the BA website says: “British Airways has been informed that trade unions representing airport workers across Portugal are threatening to hold industrial action at some airports from Friday 1 July up to and including Sunday 3 July.
“At this stage we intend to operate our normal schedule, but your flight may be delayed as a result of the industrial action.
“There may also be longer waiting times at check-in and baggage reclaim areas at certain times of the day at Lisbon, Porto and Faro airports.
“If you are flying from Portugal on one of the three potential strike days please do all you can to check-in online before coming to the airport, print your boarding pass and carry it with you.
“When flying to or from Portugal, please carefully pack your possessions with the most important items in your hand baggage as there could be issues with how checked baggage is processed through each of the airports.
“Although the industrial action is beyond our control and will affect many airlines, we are sorry for the potential disruption to your travel plans.”
BA added: “The situation may be liable to change at short notice, so please keep checking the status of your flight before travelling to the airport.
“If your flight has been cancelled, please do not travel to the airport. We have a policy in place outlining the options available to you and how to make changes to your booking.”
However, there was some relief today as Eurocontrol announced a series of planned strikes by Portugal’s air traffic control workers had been called off. They were due to walk out for two hours today, July 8, 15 and 29.