Manchester Airport has warned passengers to expect queues of up to 90 minutes due to staff shortages.
Charlie Cornish, chief executive of owner Manchester Airports Group, urged departing travelers to arrive three hours before their flight to avoid missing it.
Passengers have faced long delays and chaotic scenes in recent weeks, with queues trailing outside terminals to reach check-in desks and hordes of people waiting to get through security and to pick up luggage.
The airport’s managing director, Karen Smart, resigned on Tuesday.
After cutting thousands of jobs during the coronavirus pandemic, the aviation industry in general is suffering from difficulties recruiting staff and waiting for security checks to be passed on new employees.
There has also been a recent rise in coronavirus-related staff sickness.
Pressure on airlines and airports has increased due to the surge in demand for travel during the Easter school holidays.
Mr Cornish said: “The simple fact is that we don’t currently have the number of staff we need to provide the level of service that our passengers deserve.
“Despite our efforts since last autumn, the tight labor market around the airport has meant we have just not been able to hire people quickly enough to establish a full-strength team.”
Staff shortages mean the airport cannot open all its security lanes, resulting in long queues.
“While we still expect most passengers to get through in less than 30-40 minutes, there will be times over the next few months when waiting times will rise to between 60 and 90 minutes,” Mr Cornish said.
“We understand that people will feel anxious about missing their flights when they see queues of this length.
“So for now, we are advising passengers to arrive at the airport three hours before their flight leaves, to allow enough time to check-in, get through security and reach the departure gate.”
The chief executive said the airport is facing “one of the most challenging employment markets we have seen”, with more than half of the candidates offered jobs finding vacancies elsewhere before the aviation vetting process is completed.
But the airport does expect around 250 new security staff to begin work by early May.
Mr Cornish added that he “cannot apologize enough for the disruption people have faced” and insisted “we will be back to where we need to be soon”.
British Airways and easyJet have recently canceled a total of more than 100 daily flights, and passengers at Heathrow and Birmingham Airports have also complained of long queues.
Aviation regulator the Civil Aviation Authority has warned airlines that late-notice cancellations and excessive delays are “not just distressing for affected consumers but have the potential to impact confidence levels across the industry”.
In a letter, chief executive Richard Moriarty acknowledged that many carriers are in the process of recruiting large numbers of staff but “it is clear that this has not always happened sufficiently quickly to cope with the increased passenger travel in recent days”.
He wrote: “Given the consequences for passengers of canceled and disrupted journeys, I encourage you to do all you can to ensure that you have the necessary level of appropriately-trained and cleared staff resources in place.”
I have added that it is “very important” that airlines set schedules “on a basis that is deliverable given available staff (including contractors), and has resilience for staff sickness, including from Covid”.
Mr Moriarty also wrote to airports, calling on them to “work closely with airlines” to ensure “disruption is kept to a minimum”.