Tui has announced a “small number” of flight cancellations and delays in a blow to travel plans at the start of the half-term break.
The travel company said “various operational and supply chain issues” are to blame for the flight cancellations.
It comes after the airline EasyJet announced it will cancel more than 200 flights over the next 10 days.
EasyJet said the cancellations would affect about 24 flights per day from London’s Gatwick airport between May 28 and June 6.
A Tui spokesperson said: “We would like to apologise for the inconvenience to customers who have experienced flight delays or a flight cancellation.
“Delays have been caused due to a combination of factors and we are doing everything we can to keep customers updated, and will provide refreshments and, where appropriate, provide hotel accommodation.
“Where we have made the difficult decision to cancel a small number of flights, customers will receive a full refund within 14 days and we will contact them directly to help them try and find another holiday.
“We would like to thank our customers for their understanding and apologise for any inconvenience caused.”
EasyJet earlier said its 200 cancellations were “necessary to provide reliable services over this busy period”.
It comes after a software failure forced EasyJet to cancel around 200 flights on Thursday.
A spokeswoman for the company said in a statement: “We have taken the decision to make advance cancellations of around 24 Gatwick flights per day starting from May 28 until June 6.
“We are very sorry for the late notice of some of these cancellations and inconvenience caused for customers booked on these flights, however we believe this is necessary to provide reliable services over this busy period.
“Customers are being informed from today (Friday) and provided with the option to rebook their flight or receive a refund and can apply for compensation in line with regulations.
“Over the next week we will be operating around 1,700 flights per day, with around a quarter of these operating to and from Gatwick.”
Elsewhere, Liverpool FC supporters travelling to the Champions League final and families embarking on half-term getaways faced long queues at the Port of Dover and UK airports.
Thousands of fans descended on the Kent port on Friday to board cross-Channel ferries en route to Paris for Saturday’s match.
Airline passengers were also stuck in lengthy queues at airports such as Gatwick, Manchester, Stansted and Bristol.
There is also high demand for sailings from families embarking on trips to the continent for half-term.
The port advised passengers to “pack adequate supplies including food and water” as it is expecting “a very busy week ahead”.