British families considering a summer break in Spain or Portugal should book within the next few days because hotels are being filled by tourists looking for "certainty" after recent terror attacks in other popular destinations, Ryanair has said.
The airline claimed UK holidaymakers will be "fighting" for hotel vacancies with people from Germany after citizens of both countries were killed in Tunisia and Turkey respectively in the past 12 months.
The airline's chief marketing officer, Kenny Jacobs, said: "I was in Portugal last week talking to hoteliers.
"A lot of the hotels in the Algarve and a lot of hotels in Andalusia are already completely sold out for July and August.
"Our advice to anyone here in the UK is if you're looking to go to Spain or Portugal make sure that you book your holiday - I would suggest - by the end of February.
"People always want sunshine in July and August and the UK has the most constrained school holidays so anyone with kids is going to be fighting for hotel beds in Spain and Portugal. They already are."
Thirty Britons were killed by a gunman on a beach in Sousse, Tunisia in June last year, while 10 Germans died in an explosion in the Turkish city of Istanbul last month.
Mr Jacobs told a press conference in central London that these events have led to a reduction in Ryanair bookings for north Africa.
"There's been a drop off in demand for people from the UK going to north Africa because of the terrorist attacks last year in Tunisia.
"That has benefited Spain and Portugal because people in the UK still want to get sunshine," he said.
"With the terrorist attack where German citizens were killed in Istanbul we have seen a big reduction in Germans going to Turkey, which is a huge market for them.
"About 40% of the Germans who were planning to go to Turkey are now not going to Turkey and the first places they're looking at are Spain and Portugal."
He went on: "You just don't want the uncertainty. You don't want that when you're planning your holiday. You want certainty on sunshine and everything else to be as you expect."
Meanwhile Ryanair chief executive Michael O'Leary revealed that the airline has an "agreement in principle" with long-haul carriers Norwegian and TAP Portugal over providing feeder flights.
"We're now dealing with how we harmonise the booking systems and passenger handling.
"It's probably going to be a couple of months before we have something to announce," he added.
Ryanair has released its largest ever London winter schedule for 2016 with five new routes including Alicante, Hamburg and Toulouse, in addition to services to places such as Gran Canaria, Sofia and Vilnius which are being extended into the winter.