The MP, who is also the Shadow Transport Secretary for the Lib Dems, told the House that the airline bmi was planning to run empty flights this autumn simply to prevent it losing slots, and that Flybe was going even further, hiring actors to fly between Norwich and Dublin to boost passenger numbers.

Mr Baker asked the Prime Minister to agree that, given the huge carbon emissions from aviation, he should take action to end this 'environmental disgrace'.

In response, the Prime Minister agreed that it was wrong that airlines were running empty flights, and promised to talk to the airlines and then write back to the Seaford MP.

Mr Baker said, "It is disgraceful that these environmentally damaging ghost flights are taking place.

"I welcome Gordon Brown's admission that these flights are unacceptable and his promise to look into the problem.

"However, the proof of the pudding will be in the eating. "Will he take action or will he continue to cave in to the aviation industry, as he has done regularly over Heathrow matters?"