Budget airline easyJet has swung to a third quarter profit and is forecasting record earnings over its peak season despite cautioning over a “challenging” summer of airport strike action.

The group said it has taken steps to offset the impact on passengers from air traffic control (ATC) industrial action – with ATC strike days up 40% already in the year to date against 2019.

It recently announced 1,700 flight cancellations from Gatwick in a move expected to impact around 180,000 passengers as it looks to pre-empt ATC disruption and give a buffer in its flights programme to cope with delays.

The group’s boss Johan Lundgren said there has been no impact so far from the searing heatwave across southern Europe on demand or disruption to flights or its package holiday offers.

The Foreign Office has issued extreme weather warnings for Britons travelling to popular holiday destinations in Italy, Spain and Greece as temperatures soar close to 50C, with Canary Island La Palma also devastated by wildfires due to the heat.

Mr Lundgren, chief executive of easyJet, said the group has not seen the heatwave acting as a “deterrent” to holidaymakers booking their summer trips and has not changed its flights programme due to the weather.

The company swung to a record headline pre-tax profit of £203 million for the three months to June 30, against losses of £114 million a year ago after increasing its flight programme by 5% to 146,816.

The group said it is on course for another record-breaking profit performance in its final quarter to September 30 as it said bookings remain solid.

Mr Lundgren said: “We are absolutely focused on mitigating the impact of the challenging external environment on our customers and flying them on their well-earned holidays.”

But he said the group is facing “very congested and inefficient” ATC systems, with the “whole industry seeing challenging conditions this summer”.

“More constrained air space and flow rate restrictions are resulting in unprecedented ATC disruption as well as increased ATC strike days,” easyJet warned.

But it was given a boost recently after DHL workers at Gatwick Airport – who support easyJet operations – suspended their strike action in July and August after a breakthrough in talks over pay.

EasyJet said it is upping its winter flight programme by 15%, with bookings more than doubling year-on-year for the season.

Mr Lundgren said holidays remain the “number one priority”.