Robert McCrum, seen here looking like a cross between Antonio Banderas, Gary Busey, and that angry English guy from American Idol, looks at Ian McEwan: the brand. Now with 50% less fat?

This week, the process of McEwan’s branding took a step further when prime ministerial hopeful David Cameron chose to be photographed on the tube not reading the Economist or Beano – or playing with his Gameboy – but immersed in a copy of On Chesil Beach, McEwan’s recently published novella.

As a contemporary brand, this has already enjoyed widespread (and mainly glowing) notices and is currently high in the bestseller lists – a rare case of a serious writer enjoying both critical and popular acclaim. The McEwan brand is perfect for Cameron. It says “I like fiction. I’m in touch with my feminine side. And I support the arts.” Cameron’s endorsement is a moment of brand-recognition no amount of money can buy… Interestingly, it is more than equalled by his popularity in the US.

All this is not necessarily good news for McEwan’s publishers. In the short term, of course, their author’s high profile will guarantee acres of media coverage and commentary – and incredible sales. Further down the line, in the inevitable dialectic of literary criticism, the revisionism will begin.