I was warned about meeting David Edgar. Daunting, ponderous, awkward - and these were the descriptions from his friends. So it is a surprise when he emerges, fresh from rehearsals at the National Theatre, beaming from ear to ear. "Are we having wine? We must agree not to mention it. I did another interview where they said I started to slur my words." I may be breaking my promise here, but I can't say I noticed any slackness over lunch, where Edgar tucked into a plate of the National's sausages and mash. With a glass of wine.
Recently, he has written several political plays set in Europe and America. Why return to British politics now, in Playing With Fire? "I was a bit alarmed," he says, "to think I hadn't written a play set in Britain since That Summer, my play about the miners' strike, which I wrote in the late 1980s." When Nicholas Hytner, director of the National, asked him to fill the "political slot" at the end of the £10 Travelex season, as Edgar puts it, he was up for it. And has the press release got it right, describing the new work as a "metro v retro comedy of misunderstanding which becomes a chilling drama about multicultural Britain"? He pretends to be offended. "Actually, I wrote that."
The starting point was the 2001 race riots in Oldham, Bradford and Burnley. "I started to talk to people in local government and discovered there was an unreported war going on between new Labour and what it sees as the last bastion of old socialism in northern town halls." The first half follows an ambitious new Labourite, Alex Clifton, as he arrives in a northern town to "modernise" the councillors who have failed a government audit. "For me, the situation had elements of a classic western, such as High Noon - a stranger riding in to clean the place up. With maybe a dash of Cold Comfort Farm."
One of Edgar's "broken-backed" plays, which deliberately change tone after the interval, Playing With Fire moves from comedy to wrestle with more dangerous material. How does the political wrangling affect already strained race relations in the town? Does either side grasp how volatile things are in a community split by religious and racial ghettoes?
"I reject the idea that riots and terrorists are on a continuum from fundamentalist Islam. Suicide bombers are special cases. But do we need to renew our ideas about cultural diversity? Ask what is holding us together, as well as celebrating differences."
He says the best way to work out what he thinks about something is to write a play about it. He has also started to put elements of himself into his work.
"People tell me there's always a David Edgar character in my plays. In this one it's Jack, the character I like least. He's pretty sure he's the cleverest person in the room; he's a bit manipulative. But I'm quite fond of the leader of the council, desperately trying to find a down-to-earth compromise. He has a nice, dry wit. If I'm viewing myself more kindly, there's a bit of me in him, too."
The contradictions of Edgar's person-ality stem from his surprisingly anti-intellectual origins. He was born in Birmingham in 1948 into a long-standing theatrical family. His father, Barrie, was an actor and stage manager at the Birmingham Rep, becoming an early BBC TV producer of shows such as Come Dancing and Songs of Praise. "As a boy, I would travel around the country with him, watching outside broadcasts from theatres and end-of-pier shows. So I got a good education in popular culture." His father also built him his own theatre in a shed in the back garden. "I wrote plays with juicy parts for myself because I wanted to be an actor."
Reading drama at Manchester University in the late 1960s, however, he became a student revolutionary and resolved to work as a playwright. After a spell as a drama critic in Bradford, he was commissioned to write his first professional play by the director of a local theatre in 1970. Two Kinds of Angel involves a bizarre encounter between Marilyn Monroe and Rosa Luxemburg. "It wasn't very good," he admits.
His playwriting career hit its stride in 1976, when Destiny, his first mature drama, was produced to critical acclaim. He joined the ranks of British political playwrights such as Howard Brenton, David Hare and Michael Frayn. During the Thatcher years he busied himself in academia, founding the University of Birmingham's MA course in playwriting studies. He became a professor there in 1995.
He remains broadly loyal to the ideal of democratic socialism. How has he pulled this off when others of his age and (public-school) background have swung to the right? "I find it hard to be self-admiring in sustaining my beliefs," he says. "I've been lucky to be a playwright. I've never had to make any great moral choices like the politicians in my plays." These days he sees himself less as a participant in politics and more of an observer.
Yet does he despair of newer playwrights, perhaps less willing to tackle the political "big picture"? "Oh no," he insists, "I get more optimistic about that every day. I'm delighted to see Birmingham Rep's growing repertoire of black and Asian playwrights, young writers such as Roy Williams and Kwame Kwei-Armah. Younger writers are political, just not in the same way." He drains his glass of wine. "Playwriting is a cycle. Just when you think the theatre is dead, something new always comes up. That's how it works."
Playing With Fire runs at the National Theatre (020 7452 3000) until 22 October
An ex-soldier, frustrated by civilian life, turns to extreme politics in a party resembling the National Front. Winner of the Arts Council's John Whiting Award.
The Jail Diary of Albie Sachs (1978)
RSC adaptation dealing with the life of the South African dissident lawyer.
The Life and Adventures of Nicholas Nickleby (1980)
Commissioned by Trevor Nunn for the RSC. Edgar's most commercially successful work, this Dickens adaptation starring Roger Rees won three Olivier Awards, including Best New Play, and a Tony.
An RSC production probing the failings of the socialist left, featuring a central character who turns into a sceptic and reactionary in Thatcher's Britain.
The Shape of the Table (1990)
The first play in Edgar's east European trilogy explores the transfer of power in a former communist state from political commissars to dissidents.
Set in an undisclosed eastern European country, this art-historical whodunnit transforms into a political hostage drama. Won the London Evening Standard Best Play Award.
The Prisoner's Dilemma (2001)
Final instalment of the trilogy, produced by the RSC. Examines the back-room manoeuvres of a peace negotiation.
Continental Divide (2003)
Six-hour, two-play cycle staged at the Barbican in 2004, it looks into contemporary American politics.