Airlines condemned by PM for flying EMPTY planes to keep hold of slots at Heathrow

A bmi aircraft at Heathrow's Terminal One. The firm will fly near-empty aircraft to retain landing slots

This, it was alleged, was to preserve multi-million pound take-off and landing slots at Heathrow, which are valued at £770 million.

British Midland deputy chief executive Tim Bye said his airline would prefer to cancel such uneconomic flights - typically to the North of England or Scotland. But under 'use-it-or lose-it' rules which cover landing and take-off slots at Heathrow, the planes had to keep flying  80 per cent of the time - or be forfeit to rival airlines.

Mr Bye said: 'We have to keep them flying  to preserve our slots. What might  have been a marginal service in most winters will become even worse, partly because of the price of fuel and partly because of the drop off in demand that the general economic cycle will bring. Economic pressures will drive the demand down even more than airlines would normally expect.'

Bmi did not dispute the quotes attributed to Mr Bye, but said the way in which they had been used  had been 'a gross distortion and misrepresentation of the facts and is completely without foundation."

British Midland denied its planes would fly totally empty - with only flight and cabin crew on board - and said Mr Byes words had been 'misinterpreted.'

Bmi owns 11 per cent  of Heathrow's take off slots, second only to British Airways with 41 per cent  and ahead of Virgin Atlantic.

City experts estimate each 'slot' is worth up to £30million, though the trading of them is a black-art shrouded in much mystery.

Earlier this year budget airline Flybe based in Exeter was revealed to be advertising for actors and models to fly between Norwich and Dublin to meet passenger targets imposed by Norwich airport as part of a commercial deal.

The 'ghost plane' issue was described as an 'environmental disgrace' by Liberal Democrat transport spokesman Norman Baker during Prime Minister's question time.

Mr Baker asked: 'You may have seen in today's press the admission from the airline Bmi that it intends to fly empty planes this autumn in order to keep its slots open and that Flybe, for the same reason, is even hiring actors to fly between Norwich and Dublin to boost passenger numbers.

'Given the massive carbon emissions for which aviation is responsible, isn't this an environmental disgrace, and will you take action to prevent these ghost flights or will you cave in to the aviation industry as usual?'

Mr Brown replied: 'It would be clearly unacceptable if airlines flew without any passengers whatsoever simply to maintain their slots. We shall look at the matter that you raise, we will talk to the airlines.'

A spokesman for Bmi said the claims were 'completely without foundation' adding: 'Bmi categorically denies that it will operate empty or near empty services at Heathrow this winter in order to protect its slots at the airport.

'Bmi has never adopted such a strategy and to suggest it intends to do so this winter is a gross distortion and misrepresentation of the facts and is completely without foundation.'

The news comes a day after British Airways chairman Martin Broughton said rising fuel costs were contributing to 'perhaps the biggest crisis the aviation industry has ever known.'

BA's chief executive Willie Walsh said the airline would axe up to 5 per cent of flights, impose fuel more surcharges and increase fares by up to 4 per  cent.

Outside the Commons, Mr Baker said: 'It is disgraceful that these environmentally damaging ghost flights are taking place.'