A strike by Portuguese hazardous goods drivers has severely affected fuel supplies at Lisbon, Porto and Faro airports.
Several easyJet flights were forced to stop in Spain en route to Portugal on Tuesday (16 April) to refuel for fear of being unable to do so upon arrival.
Spanish ground handling staff, meanwhile, are currently planning strike action at the weekend and into next week.
Abta estimates more than two million Britons will head overseas over the Easter weekend (19-22 April), with temperatures of 20C to 23C forecast in Spain.
The Foreign Office has issued fresh travel advice for Britons heading to the Iberian peninsula over Easter.
“Strike action by Portuguese fuel tanker drivers since 16 April may cause disruption to flights at Lisbon and Faro airports,” said the FCO.
“If you’re travelling from Lisbon or Faro airport over the coming days, check with your airline for possible delays. Travel within Portugal may also be affected by the strike.”
Regarding Spain, the FCO added: “There are several strikes planned throughout April affecting air travel across Spain. Airport security workers at Madrid Barajas Airport began striking on 12 April; it’s unclear when this strike will end.
“Airport workers throughout Spain will be on strike on 21 and 24 April. If you’re travelling during these times, you should prepare for the possibility of delays, allow additional time, and keep up to date with your airline on the status of your flight.”
EasyJet has confirmed six flights between the UK and Portugal on Tuesday had to make fuel stops en route.
Reuters reports Portugal’s national union of dangerous goods drivers had pledged to continue striking until its conditions are met.