Virgin Atlantic, the UK long-haul airline controlled by Sir Richard Branson, said its pre-tax profits had almost doubled last year – but the results were helped by its status as a private company and the rules under which it reports its accounts.

The airline is 49 per cent owned by Singapore Airlines and figures from the Singapore group, produced under the widely adopted international financial reporting standards, show Virgin Atlantic barely broke even in the 12 months to the end of March and was heavily lossmaking in the final quarter of that period.