Britain's airports are coming under fire for failing to prepare for this week's jubilee getaway and the busy summer season, as passengers face long delays and cancelled flights.

"The UK's airports are in crisis because thousands of jobs have been slashed," Sharon Graham, head of the country's biggest trade union Unite, said on Wednesday.

The airline industry was one of the hardest-hit sectors during the Covid-19 pandemic. Flights were grounded by lockdowns and travel restrictions.

Carriers and airports laid off thousands of employees.

But deputy prime minister Dominic Raab accused airlines of a "lack of preparation" in the run-up to the holiday surge now restrictions have been lifted.

British airports have seen scores of flight cancellations and delays for passengers
British airports have seen scores of flight cancellations and delays for passengers AFP / JUSTIN TALLIS

"Throughout the pandemic, the government provided ?8 billion ($10 billion, 9.3 billion euros) of support," he told Sky News television.

"There's been some tweaks to the regulation to make it easier for the airline industry to hire.

"I don't think the airline operators have done the recruitment that they should have done, and taken the advice that the transport secretary gave them."

Thursday and Friday are public holidays in Britain as part of four days of celebrations for Queen Elizabeth II's Platinum Jubilee.

Airlines for Europe, which represents EU airlines, predicted the problem would continue "for a good chunk of the summer season".

Unions are blaming job cuts and poorer working conditions for causing a staffing crisis
Unions are blaming job cuts and poorer working conditions for causing a staffing crisis AFP / Adrian DENNIS

In response, the industry organisation representing UK-registered carriers, Airlines UK, said the sector was still emerging from "the worst crisis in the history of aviation".

"Airlines were grounded for almost two years as a result of one of the most restrictive travel regimes in the world and with this in mind, the sector has had only a matter of weeks to recover and prepare for one of the busiest summers we've seen in many years.

"Despite this, and without the ability to know when restrictions would be completely removed or predict how much flying would be possible over the summer, the vast majority of the many tens of thousands of UK-departing flights a week will be operating as scheduled."

Flights from Stansted could be affected in the coming months due to a pay dispute, the union Unite has warned
Flights from Stansted could be affected in the coming months due to a pay dispute, the union Unite has warned AFP / Adrian DENNIS

The group called for a collaborative effort between airports, airlines and the government to ensure flights take off.

Manchester Airport in northwest England has seen increasing numbers of disgruntled travellers complaining about long waits to go through security or to collect their luggage.

Some missed their flights altogether, if they were not cancelled.

One passenger posted a photo on Twitter at about 4:00 am (0300 GMT) on Wednesday showing a queue stretching out of the terminal.

"Carnage once again this morning (4am) at @manairport T1... I haven't even made it in the building this time around!" the post read.

The airport responded: "We are aware of challenges being faced by a number of airlines and handling agents, which is leading to delays at check-in and baggage reclaim for some passengers," the airport responded.

Susannah Streeter, an analyst at Hargreaves Lansdown, said mass flight cancellations were expected to increase, further heaping pressure on airlines.

"Pent up demand is colliding with a severe labour crunch for the industry as companies struggle to recruit workers for key ground roles in particular, following mass pandemic lay-offs," she said.

In Manchester but also at London Heathrow and Gatwick, and elsewhere, there have been hundreds of cancellations this week, affecting companies such as tour operator Tui, British Airways and easyJet.

To make matters worse, low-cost airline easyJet was also hit by computer problems, which forced them to ground some 200 additional flights.

British Airways acknowledged it had been a "challenging period" but it was looking to recruit massively

Schedules have been cut "to provide certainty for our customers", and passengers were being given "maximum flexibility" to rebook or receive a full refund, it told AFP in a statement.

Unite also warned that Ryanair flights out of London Stansted could face "serious disruption" in the coming months.

Struggling workers were calling for better pay after seeing a 10 percent cut in their wages in 2020, the union added.