Business class passengers famously draw envious glances from the herd in economy by turning left when they enter a plane, but it is the first class ticket holders who are the most pampered. On British Airways' 747s they ascend to their Kelly Hoppen-designed cabin and don their free pyjamas and slippers before supping on the likes of lobster thermidor, pan-seared wild Scottish salmon or roasted Cornish game hen, then slip between the sheets of their roomy – and extremely flat – bed.

Now, however, this most opulent form of travel is under threat.

The global downturn has devastated demand for expensive seats, and even Hollywood stars and bankers are shying away from BA's extravagant first class prices. The airline, stung by a slump in premium bookings that helped push the company into its worst-ever loss of £401m, has removed first class accommodation from four of its new long-haul planes, and is to review seating plans for other new aircraft.

"The long-haul aircraft that we take delivery of this year will not have any first class cabins in them," said Willie Walsh, BA's chief executive. He insisted there was no direct link to the recession, but he added: "Longer term we will review the configuration of [all] new aircraft." BA is also launching a service this year from Heathrow to Las Vegas, a prime destination for high-rollers, with no first class option.

First class is the last remnant of the more romantic days of air travel when BA's predecessor, British Overseas Airways Corporation, offered first class tickets alongside the more down-at-heel tourist or economy cabins. Its upmarket reputation has become even more rarefied over the years following the introduction of slightly less luxurious business class seats in the late 1970s, and cut-throat competition on the transatlantic market.

Walsh admitted that the cost of ripping out seats in the existing fleet is too great to get rid of first class in existing planes, leading industry watchers to speculate that upgrades for economy class travellers might become a more common occurrence. "In the short term we would have to spend money to do it and that's not necessary," said Walsh.

The review of seating layouts is taking place against the backdrop of a decline in business travel that poses a serious threat to long-haul airlines. BA relies on premium passengers for more than 50% of its revenues, more than any other major European airline. In an indication of the current mood of austerity, Walsh announced yesterday that he will work for no pay in July, and urged BA's 40,000 staff to take unpaid leave or work part-time. "This is no stunt. I do not easily give up anything I have earned," he said.

BA has seen premium bookings decline by 13% over the past six months with its north Atlantic routes, BA's main source of profits, badly hit by the crisis in the banking sector. Its rivals have fared just as badly, with premium travel since the start of the year slumping by nearly 20% across the industry. The International Air Transport Association expects business class bookings to recover once global trade picks up, but it is gloomier about the prospect of bankers flying again in the droves that have boosted BA's profits in recent years.

The recession has also reduced demand for corporate jets, emblems of excess whose use has caused serious embarrassment to companies bailed out by national governments, including some of the major American car manufacturers and RBS.

Business jet travel in the UK has fallen by 20% over the past six months, ending a boom that saw flight numbers grow by about 14% annually to 150,000 trips per year.

The cost of refitting an aircraft, at millions of pounds per plane, means that airlines will have to turn to riskier strategies such as overbooking flights until their new aircraft orders arrive. Airlines can guarantee strong revenues from economy class passengers if they overbook the back of the plane. Under that scenario, any passenger who is the victim of an overbooking could be upgraded to one of the many empty seats in business class, or bumped to another flight.