ForwardKeys, which monitors flight sales data, said a fall in consumer confidence, which began in the last week of May, “has rapidly worsened”.

It said last-minute sales for departures from London’s airports to Europe in the week running up to 10 July were down 41% on the same period in 2019.

The level of late bookings peaked at 60% above 2019 levels in mid-April this year and has declined ever since.

Olivier Ponti, ForwardKeys’ vice president insights, said: “One can think about this summer both positively and negatively. On the upside, it is encouraging to see a strong resurgence in demand following the pandemic, with summer bookings in May surging ahead of 2019 levels.

 
“However, things have come back so fast that airports and airlines have struggled to cope, which is causing chaos for the travellers whose flights are affected.”

He added the increased level of disruption was “substantially dampening demand”, with a slowdown in last-minute flight bookings and an increase in cancellations.

 
London’s airports fared better than Amsterdam, which saw a 59% slump in late sales over the same period. Amsterdam’s Schiphol airport has, like Heathrow, imposed a capacity cap while it struggles to recruit staff.

Looking further ahead, ForwardKeys said the increasing price of oil was another concern, particularly with supplies disrupted by the war in Ukraine. Rising inflation would also leave most travellers “less able to afford the fare”, it said.