The Spanair cabin crew who reportedly denied a passenger disembarkation after he expressed concerns about the aircraft were not breaking any rules. If you want to get off a plane before it takes off, you must appeal to the compassion of the crew and, ultimately, the captain.

There are no rules governing what is essentially a grey area of aviation regulation, dictated by circumstance, and even by mood. “It depends on the circumstances,” a spokeswoman for British Airways said “and is entirely at the captain’s discretion although it happens rarely."

Rival British carrier, Bmi agreed that it was also a rarity. Bmi passengers who wish to disembark can do so at any time before take-off, although the safety and security of others has to be taken into account. A spokesman said: “Once the airbridge has been removed and the aircraft pushed back, it’s difficult to disembark a passenger, but obviously we would in a medical or other emergency.”

The Civil Aviation Authority, which regulates the UK aviation industry, says that it has no official line.

A spokesman added that issues regarding take-off slots, retrieval of luggage and the implications of a lengthy delay for 300 or 400 passengers are all taken into account.

Conversely, airline regulations resolutely dictate that an airline can kick a passenger off the plane any time they like – incidences include Dr Paolo Tomasi’s ejection from a Ryanair aircraft for talking to his son during the safety briefing, and the Hooters waitress Kyla Ebbert, who was ejected from a Southwest Airlines plane in San Diego for being dressed too provocatively.

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