Don DeLillo's 827-page alternative history of post-war America, Underworld, secured his reputation as one of the most substantial writers of his time and inevitably attracted that cliched label 'the Great American novel'. However his latest work, Cosmopolis, has been met with less enthusiasm by critics.

Cosmopolis follows 28-year-old billionaire Eric Packer for just one day as he goes in search of a haircut in New York. His journey is frustrated by gridlock and Packer is forced to conduct his day's affairs in the back of a marble-floored limo. Exploring familiar themes - the alienating force of money, consumerism, and a bleak assessment of technology - it's a dark and sometimes difficult read.

DeLillo is a reluctant interviewee. When Jim Naughtie caught up with him at the Hay Festival of Literature, he declared: "I have no answers". But his books ask a lot of questions. "At some stage," he said, "a writer must think about writing against the power of the state, the corporation, the endless process of rampant consumerism and waste." That's Cosmopolis. And while critics can question it, they can't ignore it.