Passengers at London's Heathrow Airport, the largest in the United Kingdom, spoke of scenes of "total chaos" after 30 flights were removed from Thursday's departure schedule at short notice, because of fears about passenger overcapacity.

With the summer travel season still nowhere near its peak, some passengers were unaware of the cancelations until they were at the airport, and spoke of lengthy queues and customer service struggling to cope.

"We will work with airlines to get affected passengers rebooked onto other flights outside of the peak so that as many as possible can get away, and we apologize for the impact this has on travel plans," said a spokesman for the airport.

"We are working hard to ensure everyone has a smooth journey through Heathrow this summer, and the most important thing is to make sure that all service providers at the airport have enough resources to meet demand."

The incident comes less than two weeks after other Heathrow flights were cancelled because of problems handling the volume of baggage, and with the prospect of further disruption later in the summer after British Airways ground staff voted to take industrial action.

Earlier in the week, Heathrow bosses warned passengers could face years of disruption following the decision of the Civil Aviation Authority, or CAA, to reduce the cap on landing fees from the current figure of just over 30 pounds ($36.37) to just over 26 pounds by 2026, after lobbying by airlines.

CAA chief executive Richard Moriarty said it was an impartial decision "about doing the right thing for consumers" but Heathrow chief executive John Holland-Kaye said the CAA "continues to underestimate what it takes to deliver a good passenger service, both in terms of the level of investment and operating costs… uncorrected, these elements of the CAA's proposal will only result in passengers getting a worse experience at Heathrow as investment in service dries up".

There were chaotic scenes at airports across the UK at Easter and around the Platinum Jubilee holiday weekend, as the aviation industry, which has been so badly affected by the pandemic and as a result has cut staff numbers, struggled to handle demand.

In a bid to avoid a repeat of such scenes, the government has drawn up a 22-point plan for airports.

"While it's never going to be possible to avoid every single delay or cancellation, we've been working closely with airports and airlines to make sure they are running realistic schedules," said Transport Secretary Grant Shapps.

"The measures … set out what we're doing to support the industry. It's now on airports and airlines to commit to running the flights they've promised or cancel them with plenty of time to spare so we can avoid the kind of scenes we saw at Easter and half term."