But while Ryanair's competitors face financial Armageddon, experts say the low-fares airline will be able to keep its promise not to introduce fuel surcharges, even if prices go as high as $105 a barrel.

Ryanair has a much higher financial pain threshold than any of its rivals because of its lower costs and higher profit margins. Davy analyst Stephen Furlong said that, based on its projected financial performance for this year, Ryanair could continue to make a profit even if oil prices rose as much as 50% from current levels. Crude oil hit a record price of $74 a barrel in New York on Friday.

Aviation fuel, or jet kerosene, is the biggest single cost item for airlines. It accounts for fully 38% of Ryanair's entire annual cost base. Furlong puts Ryanair's break-even oil price at $105, meaning the airline could theoretically continue to make a profit right up to that level without raising fares or having to cut costs elsewhere.

By contrast, Easyjet, Ryanair's nearest rival in the European low-cost sector, would see its profits wiped out at $88 a barrel, according to Furlong's analysis.

Goodbody Stockbrokers' analyst Joe Gill was more conservative in his projections for Ryanair. According to his financial model, the airline's break-even oil price is ?between $90 and $95". At that price, he said, Easyjet would lose about £80m a year.

In practice, Gill said, if oil prices were to rise to that level Ryanair would have to respond to the pressure on its profit margins by raising average fares, but it would still be in a much better position than its competitors. He said ?50% to 60% of the European airline sector would be gone bust" in that scenario.

Aer Lingus became the latest airline to buckle under the pressure exerted by oil prices, which have risen by more than 80% over the last year, when it announced on Friday that it would start charging its long-haul customers an extra 35 each way.

Aer Lingus chief executive Dermot Mannion said the airline had no choice but to impose surcharges for the first time in its history as it could ?no longer fully absorb these costs".

Mannion's announcement provoked scorn from Ryanair boss Michael O'Leary. This is clearly unjustified, when at the very same time Aer Lingus is absorbing higher oil prices in the case of shorthaul tickets, " he said.