POLITICS is proving the biggest draw at this year's Edinburgh International Book Festival, with personalities as diverse as the Italian author and anarchist Dario Fo and the BBC's former political editor Andrew Marr selling out their appearances.
The festival, which opens today, offers a powerful forum to talk about dangerous issues including suicide bombings and the Iraq war, said the director, Catherine Lockerbie.
While the festival's line up includes literary heavyweights such as Margaret Atwood and John Irvine, political events have sold out faster than others. Sell-outs include talks by politicians Neil Kinnock and Clare Short, political journalists Jon Snow, James Naughtie and Rageh Omar, and an appearance by controversial cartoonist Steve Bell.
"Some of these events have sold out first, and I don't think it's a coincidence," she said. "People are making a beeline for them. I think this is the most political festival season ever."
Dario Fo, the author of The Accidental Death of an Anarchist, which sees several different productions on this year's Fringe, is making two appearances.
An anarchist and satirist, he won the Nobel Prize for literature. The title of his 1974 play, We Can't Pay! We Won't Pay!, also became the slogan of anti-poll tax campaigners.
Many writers at the festival have crossed the line into politics, said Ms Lockerbie. "The boundaries are fluid. It's not that in the book festival, there are the pretty poets and the nice novelists in the one box, and there are the politically motivated people in the next box."
The line-up includes Andr Brink, a South African writer of the anti-apartheid generation whose early works were banned, along with a young Zimbabwean writer, Ian Holding, with a highly political novel about violence against whites, she said.
Salman Rushdie, the author sentenced to death in a Muslim fatwa after his novel The Satanic Verses was published, is coming to the festival for the first time in 20 years. "He is a novelist plunged into a profoundly political situation by dint of writing a work of fiction," said Ms Lockerbie.
"Our festival is not about people off the telly. It's not because these are well-known names from television that people are coming. It's because they actually want to hear what they've got to say, and question them.
"Or course people are eager for some inside stories, some anecdote and gossip, but also desperate for informed opinion on what on earth is going on out there in the world."
This year's festivals are tackling terror in their own way, from comedy acts on the Fringe playing off London's reaction to the Tube bombings to the opera Death of Klinghoffer in the Edinburgh International Festival, based on the true-life murder of a United States man by Palestinian terrorists.
"I started work in the autumn not knowing what would happen in August," Ms Lockerbie said. "I have events in this programme about suicide bombers and about the causes of terrorism. These are things I wanted to look at in some depth, but when I programmed them several months ago I had no idea what topicality they would take on."
Events involve the Oxford sociologist, Diego Gambetta, editor of the recent book Making Sense of Suicide Missions, which covers in its range from the 3,000 Kamikaze pilots in the Second World War to an analysis of the current state of al-Qaeda.
The author Barbara Victor published an in-depth study of Palestinian women suicide bombers - and more recently of US evangelical Christians who believe a war against Islam is predicted in the Bible.
Ms Lockerbie said: "It is very difficult at present to talk about any of this in a relatively calm and civilised atmosphere.
"If a politician or a public figure stands up and says 'I want to understand what drives people to be suicide bombers', they are accused of being apologists for terrorism.
"We need to create a climate and we do create it within the book festival. There is a kind of instantaneous knee-jerk reaction that you are somehow excusing atrocity if you try to understand the reasons behind it - I simply don't accept that line of reasoning."