Holidaymakers are being told to bring "plane picnics" when travelling, which could result in many paying over the odds for food at airport terminals.
TUI warned that all short-haul and some long-haul flights could take off without catering on board because its supplier had been hit by staff shortages.
The airline told customers to bring their own food and drinks in case of disruption to its onboard services.
Liquids over 100ml must be bought in the airport after customers clear security and TUI only allows passengers to take one piece of hand luggage on board for free, leaving little room for packed meals.
High levels of Covid staff absences
TUI said it was "continuously monitoring the situation and working closely with our suppliers to limit the impact to the onboard service for our customers. We are directly contacting all customers impacted. We’re very sorry for any inconvenience caused".
It comes as the entire aviation sector struggles to cope with staff shortages now that international travel has bounced back after the pandemic. Airports say they are hiring more staff but they are unable to get security clearance for new hires quickly enough and are also dealing with high levels of staff absence because of coronavirus infections.
The persistent bottlenecks mean airlines are having to cancel flights and holidaymakers are facing long queues and delays at airports.
Both Birmingham and Manchester airports were asking passengers to start queuing outside the terminal buildings on Monday as they couldn’t get them through security quickly enough. Passengers described scenes of "absolute chaos" and some missed their flights as a result of the delays.
Birmingham Airport, which laid off nearly half of its employees during the pandemic, said queues were "long, but managed and moving", while Manchester Airport said most passengers were passing security in 30 to 40 minutes but admitted that queues could be more than double that.
Airlines reduce capacity and cancel flights
British Airways has cancelled a tenth of its flights from March until the end of October, which is the equivalent of 8,000 round trips. EasyJet is removing seats from some of its planes to allow them to fly with three cabin crew instead of four, leaving them less vulnerable to staff shortages.
The move will reduce capacity on some of the carrier’s planes from 156 to 150 passengers. Under UK law, flights must have "one member of the cabin crew for every 50 or fraction of 50 passenger seats installed in the aircraft".
Easyjet said: "This summer we will be operating our UK A319 fleet with a maximum of 150 passengers onboard and three crew in line with CAA (Civil Aviation Authority) regulations.
"This is an effective way of operating our fleet while building additional resilience and flexibility into our operation this summer where we expect to be back to near 2019 levels of flying."
TUI said: "We can confirm that unfortunately due to staff shortages with our catering supplier, there may be limited food and drinks services available onboard TUI Airways short- and mid-haul flights over the coming days.
"Customers may therefore want to bring their own food and soft drinks onboard (no alcohol permitted). Any soft drinks over 100ml will need to be purchased after you have passed through security. Please note this disruption does not affect any long-haul flights to Aruba, Costa Rica, Cuba, Dominican Republic, Jamaica, Mexico, Orlando and St Lucia and meal services on these flights will continue to operate as normal."
