Portuguese airport security staff strikes may well delay British holidaymakers travelling for the Easter weekend.
The FCO are advising passengers to reduce their luggage that need screening.
EasyJet has said that passengers will have longer queues due to the strike until Monday.
EasyJet said: “We have been informed that airport staff will be there to reduce any impact caused by the strike.”
“However, we strongly recommend that you allow extra time for your journey through the airport to be able to get to the gate on time.”
A British Airways spokeswoman said: “We intend to operate our normal schedule of flights, but you may face longer waits at the central security search area at some points on each of the days.”
They further said the departure area at Lisbon airport will be “particularly affected.”