Speaking at the Airlines 2022 conference, Walsh, a former British Airways, Aer Lingus and IAG boss, criticised the airport’s “appalling inability to do a basic function”. “Heathrow remains a major problem in my opinion," said Walsh. "It’s largely been down to Heathrow’s inability to get people through security."

He added other airports had had issues but had now overcome them. “The ones that have extended beyond what we would consider to be reasonable are Heathrow and Schiphol – and the CEO of Schiphol lost his job," Walsh continued. "There is a message there.”

He branded Heathrow “a monopoly infrastructure supplier”, whose attitude to expenditure was “you have to guarantee our profitability or we won’t do it”. “You don’t have airlines saying that,” Walsh said.

He singled out Heathrow chief executive John Holland-Kaye for criticism. “There is clear evidence that the disruption at Heathrow disrupted the pattern of recovery and definitely suppressed demand," said Walsh. "I think the government and the CAA could have been more vocal. Allowing John Holland-Kaye to point the finger at airlines and say it is the airlines’ fault is unacceptable.”

Walsh accused Heathrow of not registering true queuing times by stopping passengers before they had reached the first checkpoint and only recording waiting times once travellers reached security. “Those times were not counted… according to them, you just wanted to hang around outside”.

Many airports pointed to Brexit as a source of their recruitment difficulties. Walsh said: “I have not heard a single politician express an economic Brexit benefit. I can’t see anything six years on that people are doing to maximise the value of that.”