Sarah Sands: We call it high society because they only fly first class

A new novel by Kay Burley, the Sky news presenter, promises to illuminate the corridors of power. The star of the book is "a sexy television reporter who will do anything (or anyone) to get to the top". No clues there, then. While it is the novel's sex scenes that entertained the press last week, an astute reviewer, Zoe Williams, noticed that the author and her fellow Westminster villagers were far more excited by business-class flights.

In real life, the powerful are indeed obsessed by flight status. The Blairs, for example, seemed tormented to discover that their power could not be readily leveraged into trappings. Their rich, irresponsible friends in the City could afford better holidays and means of getting there. Some of Tony Blair's critics have sneered at his disembodied post-Downing Street existence. Haven't they watched Up in the Air? To Blair, and Kay and the rest, business- or first-class flights are pretty much reasons for being.

For those without cabin mobility, flying is simple. The very rich pay (mostly, not always) to turn left. Almost everyone else goes right. But for the Kay classes there is a nerve-shredding question. Can you get your bosses/clients/hosts/to pay? Or get an upgrade?

Tatler has revealed that airlines divide us into SFU people (suitable for upgrade) and NSFU. My favourite upgrade story was told by an English business executive invited to his company's American power summit. Taking pity on an enthusiastic colleague who was never invited, the executive petitioned the boss on his colleague's behalf. The boss growled that the colleague could go, as long as he flew economy and didn't try any fancy stuff such as a taxi to the airport. The executive was a frequent flyer and a holder of that most coveted power symbol, the premium card. On arrival at the airport with his breathless colleague, both were upgraded to first class.

As the colleague sipped his first glass of champagne, he spotted the boss heading into business class. Ashen-faced, he whispered to the steward and got himself downgraded, to economy....

How has John Simpson managed to keep business class in his contract? The BBC bundles its other reporters to the back, which may explain the internal pleasure taken in Freedom of Information revelations about the flights of the director-general, Mark Thompson.

The politics of air envy run deep. David Cameron and George Osborne have made much of holiday trips on easyJet. But Cameron cannot wipe the memory of his school trip on Concorde, where he raised a glass of Dom Pérignon 1978 and declared "Good health, Sir!". This, more than his entire political career, is what sticks.

Sarah Sands is the deputy editor of the 'London Evening Standard'