The boss of Silverjet today rejected speculation that the business class-only airline is on the verge of collapse after the second of its two major rivals folded over the weekend.

"We are not going bust," Lawrence Hunt, the founder and chief executive of Silverjet declared today after news that Eos has followed MAXjet, which went bankrupt at Christmas.

But with Silverjet still needing to attract new investors - German airline Lufthansa has been named as a potential bidder - after missing break-even targets, Hunt conceded: "Things are very tough and a lot more challenging than six months ago." Citigroup analyst Andrew Light, said: "Eos is the sixth scheduled airline bankruptcy since December.

"Interestingly, experimental new business models have been the most common failures, driven by record fuel prices, softening demand and lack of access to capital to cover start-up losses in addition to the dubious viability of new business models for airlines."

Shares in Luton-based Silverjet, 1/4p better at 143/4p, have crashed more than 90% since floating two years ago. The airline has been flying since January 2007.