Recently, bmi has been forced to admit that it has decided to operate flights from London Heathrow Airport on aircrafts that are nearly empty, in order to retain the landing and take-off slots that are highly costly. This has been noted by a reporter of The Times.

According to the airline, the passenger numbers are expected to significantly fall during the forthcoming months due to the worsening of economic condition. At the same time, the airline said that it can never manage to relinquish the highly coveted slots enjoyed presently at the Heathrow terminal.

Presently, the Heathrow Airport functions to its total capacity. Therefore, a new 'use-it-or-lose-it' regulation has been implemented which means that an airline would have to sacrifice a slot if it fails to operate at a capacity of 80 per cent.

Under the present circumstances, the airline has decided to operate what is known as 'ghost flights', in order to retain the costly slots till the passenger demand rises once again. However, this decision by the airline has invited serious comments across the industry and from the critics.

Gordon Brown, the British Prime Minister has called the practice as "clearly unacceptable" and is arranging for a full investigation. Norman Baker, the transport spokesman for the Liberal Democrats, went a step further to brand this practice as an "environmental disgrace."

At present, bmi owns 11 per cent of the take off slots at Heathrow, with one of the more valuable slots alone valued at up to £30 million.