Bush's belief that he's guided by God was to blame for the war and other of America's woes, Vidal said.

'Once God comes into it with his phone calls, there's no way you can get out of it,' he said. 'He pulls rank on the president. And that's why we're where we are in many cases.

'God always talks to US presidents. He's registered somewhere in Illinois.'

Vidal was no less scathing of the media, chastising the press for 'infantilising' the American public. 'God knows, no issue can be discussed in public that's not patriotic,' he said.

You could 'light up a city' with the energy The New York Times had expended trying to stop people reading himself and Norman Mailer. 'And it doesn't work. We still are read. The New York Times is losing advertising revenue, even as I sit here.'

It was word of mouth, not slick marketing, that sold books, he said. 'One person reads a book and passes it on.'

Vidal had been 'appointed a writer for life', he said. 'Not many people have that fate, and there's something rather lunatic about being 'a writer for life', but that's what I am. And so I write. And people read.

'There's nothing unique about my perceptions and by just telling a simple truth, you'll attract an audience. I don't see there's any other way to do it.'

He joked that he had revived neglected literary reputations in his essays 'out of self interest'. 'What I have done for other writers from the quick and the dead, I trust someone will do for me,' he said.

Vidal, who is these days wheelchair-bound, rose to accept the standing ovation that followed, sending the audience into rapture.

Another author with an eye on posterity was novelist and travel writer Jan Morris.

'I'm working on my posthumous book, which I'm glad to say I have already sold,' she declared on Wednesday night. When moderator South China Morning Post editor- in-chief Mark Clifford said he hoped the book would not be published after her death, Morris corrected him. 'It certainly will be published posthumously, because I don't want it to be published before,' she said.

'I wrote my final book, which is about Trieste. I was proud of it and I didn't believe I could do something as good again, so rather than go down hill I decided I wouldn't publish any more books. But I had a book in me that I wanted to one day see the light of day and so I arranged with Faber & Faber to write it now, and they would publish it when they read in the paper that I was dead.' The book would 'appear the day of my death, when my obituary appears in The Times'.

Fellow travel writer Simon Winchester described how he came to be on stage with Morris. As a young geologist working in Uganda in 1966 it was Morris' account of the expedition that conquered Mount Everest in 1953 and the young Times correspondent's race to deliver the news to London on the morning of Queen Elizabeth II's coronation that had ignited his passion for writing, he said.

'I wrote to [the then] James Morris, care of Faber & Faber: 'Dear Mr Morris, I am a 21-year-old geologist living in east Africa and I've just read Coronation Everest and, basically, can I be you?

He said, 'I had this wonderfully kind letter back saying: 'By all means, if you think you can write then my advice to you is very simple: On the day you receive this ... go into the office of your company and resign, come back to England and get a job on a local newspaper and write to me then.' And that's what I did.'

The festival ends on Wednesday