Sir Richard Branson will be absent from next month's launch of Virgin America, an almost unheard of occurrence for the media-savvy entrepreneur, which highlights the sensitivity of overseas involvement in the US airline industry.

Virgin America, a San Francisco-based start-up, provided a lightning rod for the bipartisan opposition in Congress and among US unions to reforming the strict investment laws governing the sector, which this week resurfaced and threatened to undermine the "open skies" treaty agreed in April with the European Union.