Heathrow has asked airlines to cancel 10% of their flights today as the airport faces a baggage backlog.
Problems with the baggage system left hundreds of travellers waiting for around three hours over the weekend to retrieve their luggage, with no explanation from staff.
It is unclear how many airlines will comply with the request, but thousands of passengers are expected to be affected.
Airlines that have cancelled flights today include Virgin Atlantic, Flybe, Air France, Air Canada, TAP Portugal, Loganair, British Airways, Delta Air Lines, Brussels Airlines, Scandinavian Airlines, Aer Lingus, ITA Airlines, Eurowings, Lufthansa, KLM and Bulgaria Air.
A Heathrow spokesperson said: "We apologise unreservedly for the disruption passengers have faced over the course of this weekend.
"The technical issues affecting baggage systems have led to us making the decision to request airlines operating in Terminals 2 and 3 to consolidate their schedules on Monday 20th June.
"This will enable us to minimise ongoing impact and we ask that all passengers check with their airlines for the latest information."
Heathrow, like airports and airlines across the country, is grappling with staff shortages during the busiest season of the year, which have led to hundreds of flights being cancelled in recent weeks.
On Friday, an "enormous luggage carpet" was spotted outside a Heathrow terminal, as staff grappled with an "ongoing issue with the baggage system".
Travellers told Sky News there were huge queues at border control upon landing and large crowds at baggage reclaim over the weekend.
Some passengers had been forced to travel without their belongings.
Meanwhile, easyJet announced plans to cut more flights over the busy summer period, as it apologised to customers for failing to "deliver the service they have come to expect from us".
A number of flights will be cancelled into and out of Gatwick in response to the airport's announcement last week that it would introduce flight caps in July and August to help it cope with a staff shortage.
The airline has blamed staff shortages in ground handling and at airports, as well as air traffic control delays for increased turnaround times, delayed flights and cancellations.