British Airways and Easyjet are reported to be sending text alerts to customers warning of delays at EU border controls.
BA said it is asking travellers to arrive early as the carrier is expecting longer queues due to "enhanced immigration checks" across Europe and has messaged customers flying back from Lyon, Madrid, Barcelona and Milan, BBC News reports.
Easyjet advised passengers to check the latest travel information pages on its website, adding that it "strongly recommends" customers to allow extra time to get through the airport to the gate on time.
Meanwhile Ryanair is advising customers to arrive “at least three hours before the scheduled departure time” due to the lengthy waiting times to clear security at European airports seen this week.
A spokesperson for airline lobby group Airlines for Europe (A4E), told BBC News: "It seems the governments especially in France, Italy, Spain, Portugal and Belgium underestimated the situation of many passengers going through tighter passport checks and have not provided a sufficient amount of border control officers."
He said passengers should also expect delays at airports in Majorca, Malaga, Lisbon, Lyon, Brussels, Milan and Paris-Orly.
Aviation minister Lord Callanan said earlier this week he would urge his counterparts in Portugal, Spain and Italy to "do all they can to reduce queues and allow travellers to get on with their holidays".