Billy Bragg performing at Greenbelt. Photo: Marcus Perkins/Greenbelt
'You can't change the world by writing songs about it and that's a shame, but it's the audience's job to change the world, my job is just to sing about it.'

On August Bank Holiday Monday, the 2003 Greenbelt festival closed with a set from Billy Bragg. Blunt, passionate and down-to-earth, Bragg is a people person. He writes songs about people getting a raw deal and asks his audience to be his messengers. As he says below, he can't change the world all by himself, but together with those who listen to his music the world can become a better place.

At the press conference he walks in sharing a joke with four large men wearing leathers, shades, tattoos and 'Billy Bragg Security' t-shirts. Does he need such a high profile security presence? No. They're just a loyal group of fans who go to all of his concerts. They've become his mates and they'll happily go to press conferences to hear him speak and he's happy for them to be there. No hints of stardom or 'do you know who I am?' He's just Billy Bragg.

Why are you playing Greenbelt?

"It's those two words - Trade and Justice. The political nature of what Greenbelt is doing today [the Monday of the festival was Trade Justice Day] is the reason why I'm here. They've been asking me for a while and I think this year it's been one of those events which for me, has been the right weekend, which always helps, and the right time for me because I've not been on tour doing loads of stuff, and it's the right issue.

"I've said for a long time, it doesn't matter where you come from, if you want to live in a better world then I'm prepared to work with them. It's taken me a while to play here because it's over the Bank Holiday weekend and there are so many other concerts. I'm now also a parent and I don't work through the summer holidays. It's not about 'do I want to do this festival', it's 'can I fit it in this year?' I've played Leeds and Reading this weekend - there was a bit of a different vibe there - and now today my dressing room is a betting office. I'm known as the Bard of Barking - barred from the betting office, barred from the pub… ask me another question!"

I believe one of the reasons you went into music was Spandau Ballet …

"Yeah, in the same way that Margaret Thatcher made me political. I went through the cleansing fire of punk rock in the 70s, and I believed that The Clash were going to change the world by making records, which was a bit naïve of me. I was in a band but that came to nothing so I ended up back at my mum's, so I pressed the 'eject' button on my life and joined the British Army and trained to be a tank driver.

"If you've driven one tank you've driven them all - it's not all that it's cracked up to be, so I bounced back out of there without completing my training, and one day saw Spandau Ballet on Top of the Pops, wearing kilts singing 'Chant no.1' and something in me snapped. I was waiting for a band to come along and play the music I wanted to hear and none was forthcoming. I then realised that it would have to be me, so I went upstairs, picked up my guitar and everything has been a blur until I arrived on site today!!"

How long have you been writing songs?

"Ever since I was 12. The very first thing I wrote that anyone took any interest in was actually a poem about Jesus I wrote at school. I can't remember any of it apart from the pay off line which was 'There's some hope for mankind that he'll come back some day.' My English teacher asked me where I'd copied it from, then my parents got a letter from him asking if I'd copied it from a book, then I got to read it out at the school assembly then on local radio.

"That was the first vibe I got that I could actually do this. Thirty years ago when I was at school my father bought me a guitar and the kid next door taught me how to play. When punk came along I developed my own style and when I got back to my mum's I realised it wasn't going to happen for me. Then the intense experience of [Army] basic training made me write more songs. In the words of John Lee Hooker 'If it's in him, it's got to come out.' I worked in a record store for another two years and them emerged as the butterfly Billy Bragg that you know me as now!"

Why did you join the Army?

"Perhaps it's a mark of how unpolitical I was as a young man. I would argue that in the context of the time I joined the Army - 1981 - that Thatcher and [President Ronald] Reagan were winding up the Cold War, Tito had just died in Yugoslavia, Solidarity was going off in Poland, the fan/shit interface was coming up very quickly and I though well where did I want to be when it all went off? Do I want to be sitting on my arse in Barking waiting for it to happen or go in the first burst? In some ways it was a very punk thing to do, the antithesis of people thought I would do. It was a sabbatical for me. It made me realise how much I needed to do what I do now. I wouldn't be the Billy Bragg I am now without that experience."

What are your religious views?

"My religious views are expressed in some of the songs that I sing, there's a song called 'Upfield' from the 'William Bloke' album which expresses where I'm coming from, that sense of spiritualism, in the very broadest sense of having been in touch with in the way that Blake explained it, in nature, the eternal and those kind of things. I'm not a great one for organised religion, I have a problem there, and with William Bloke I was trying to evoke a 'someone who wears a football shirt but also appreciates the beauty of a sunset and of nature' place and position in things.

"So, not in a strict church-going sense I don't have religious beliefs but spiritual beliefs. Religion was never big in our house but neither was politics or music. My mum was a Catholic but she married a Protestant so she couldn't continue to be a Catholic, so we weren't churchgoers. However, when my Dad died 26 years ago my mum's faith was a huge strength to her and I have a lot of respect for that, for people who do find great strength in their faith. It got my mum through so I'm very tolerant of those kind of things."

With what's happened to the Church of England recently, will you be playing 'Sexuality' tonight?

"Most certainly and finishing off with the line 'You can be what you want to be unless it's Bishop of Reading'! No disrespect to the Archbishop of Canterbury but people in openly gay relationships is everyday reality. How can the church deny them that great spirituality?

"I went to see The Clash in 1978 at a 'Rock Against Racism' gig in Hackney and it was the first political thing I ever did - I went to oppose the racist National Front. Tom Robinson actually closed that gig with a song called 'Sing if you're glad to be gay' and when he sang that, all the geezers around me started snogging each other and until then, I don't think I'd met an 'out' gay man. My initial feeling was 'why are these gay men at this gig? It's to support Black and Asian people - what are they doing here?'

"But it didn't take me long to understand that racists or fascists are afraid of anything that's different and it's all part of the same struggle so I pledged from that day to be as different as I could and to ask as many questions as I could about their warped and narrow view of the world. You can't change the world by writing songs about it and that's a shame, but it's the audience's job to change the world, my job is just to sing about it."

Do you think a time will come when you'll lose some of your passion?

"There's nothing wrong with calming down for a time but I think that one of the reasons I'm writing about 'Englishness' at the moment is that's because it's on the agenda. My job is merely to reflect what's going on in the country. I don't write about the great threat that the Tories are anymore for obvious reasons. They're just not on the radio anymore but the BNP are and that's got to be dealt with and put into place.

"Beyond them, occasional racism and xenophobia is poisoning our debate about the rights of people to come to our country and make a living and bring their children up somewhere safe, and whether we have anything to fear about having a European flag on the back of our coins or not. Once the Euro debate starts then there'll be some nasty little shits come out of the woodwork. To see the BNP win seats means that I can't [lose my passion] because that's all the more reason to be engaged. It's because the alternative is to give up and be cynical and I think cynicism is our greatest enemy in trying to make a better society."

What would your message to the World Trade Organisation be?

"I would like the WTO to be accountable. I would like it to be accountable to the citizens of the societies it represents and to the societies it tries to deal with. I think the lack of accountability with the WTO, the IMF and the World Bank is one of the biggest problems. Particularly the IMF because it's our tax money that they're using there and we should have some control over that."

• www.billybragg.co.uk
• Reports from the WTO meeting in Cancun
• Christian Aid's Trade Justice campaign