Ska wars: Why isn't Jerry Dammers playing on The Specials' sell-out reunion tour next month?

They made a model of me," says Jerry Dammers, picking up a plastic figurine from a shelf beneath his vinyl record collection. It's a miniature Rude Boy, with dark suit, porkpie hat and even the gappy smile that has been Dammers' trademark since he went over the handlebars of his bike as a schoolboy.

That gap grew wider when Dammers, aged 19, lost another molar to a pint glass thrust into his face in a nightclub in Coventry, the city that later inspired him to write "Ghost Town" and "Nite Klub" and other songs that defined the early-1980s and made The Specials one of the most distinctive and important bands in British popular music.

Amid great excitement, a series of concerts billed as "The Specials 30th Anniversary Tour" will take place across Britain, starting next month. The tour is already sold out. But it seems the audience will see nothing of the man who assembled this seven-piece band and forged its genre-defying sound, one that fused the defiant optimism of Jamaican ska with the anger of punk, alongside lyrics that reflected the dearth of opportunity in Britain's decaying industrial cities at the start of the Thatcher years.

Dammers is composing himself ahead of trying to explain why a reunion of the band he had been planning since the age of 10 will – as things stand – involve the six other members of The Specials but not him. He puts down the figurine, commenting that it is "some Carnaby Street tat". Dammers no longer wears the Rude Boy uniform of cropped hair, sharp skinhead-style two-tone tonic suit and shades; he has a clump of beard and long hair pokes out from beneath a Homburg hat. His jacket is tweedy and his blue shirt patterned, his loafers are no longer black but soft and brown.

Dammers may have spawned a youth cult, but he did so from a sense of individuality rather than tribalism. When he goes on stage these days his garb is an outlandish mix of ancient Egyptian and intergalactic traveller. He is leader and keyboard player of the 18-piece Spatial AKA Orchestra, which is inspired by the music of the American free jazz legend Sun Ra, playing what he describes as "21st-century" music.

Dammers' instincts have always been progressive. Yet the legacy of The Specials endures; on the wall of his flat in Brixton, south London, is an ageing poster for "Too Much Too Young", The Specials' first number one hit from 1980. But, at 53, Dammers now fears that the achievements of his younger years are in danger of being written out of history. "Through my teenage years I was writing songs, playing in club bands, but at the back of my mind was the day when I would form my own band. That's why what is happening now is so horrible to me because it's as though my whole youth, my whole life, is being stolen," he says. And what a youth it was, playing early hits such as "Gangsters" and "A Message To You, Rudy" to packed houses. "The whole place would be bouncing up and down in unison; whole buildings used to shake with the excitement at that time," he says. "We played at an old theatre in Southend and holes started appearing in the floor and kids started disappearing into the cellar 12 feet below. It was a miracle no one got seriously hurt at those gigs."

It was never going to be easy to replicate that feeling 30 years on, especially after the group's acrimonious break-up in 1981. After just two albums, singer Terry Hall and backing vocalists Lynval Golding and Neville Staple left to ' form Fun Boy Three. Back then, as now, Dammers was trying to challenge himself musically. "At the beginning of The Specials it was fine, but when it came to the second album I wanted the music to progress, because the first album is all just three-chord tricks. I introduced the muzak and exotica elements, which was radical at the time," he says.

Though he subsequently produced "Ghost Town", the band's masterpiece, his desire to experiment was not welcomed by some of his fellow band members. "I think that's maybe what the band don't like about me," he says now. "My ideas are radical, and hopefully they always will be." But he would still have liked to be part of this reunion. "I know for a fact from the way this thing has been advertised as The Specials' 30th year reunion that a lot of people have bought tickets assuming I was in it, and that it was the complete Specials," he complains. Over the past two years, negotiations have been taking place to bring the band together, a process as fraught as the original break-up. "I think I've been completely reasonable, rational and level-headed throughout this entire thing. I haven't expected anything unreasonable from anybody. I have been treated in the most despicable manner." (For their part, the other members of The Specials state: "To respond would only give credence to [Dammers'] claims. We are far too busy preparing for the sold-out tour to do that.")

A couple of rehearsals took place, though not with all band members present. Dammers was keen to do more than just replicate The Specials' early work: "I had lots of ideas for how to do this in a way that's a bit more interesting, just tweak it to make it more modern and not just a nostalgia knees-up," he says. But the arguments continued as old personal differences surfaced. Dammers was upset by the involvement of some of Hall's friends and advisers, including Simon Jordan, the mobile-phone entrepreneur and chairman of Crystal Palace Football Club. Dammers wanted nothing to do with them.

Dammers began composing some of the early Specials songs on the family piano, developing his musical ideas while studying art at Coventry's Lanchester Polytechnic. He began putting together the band that started out as The Automatics, morphing by a succession of name changes to The Special AKA. "The Specials, I handpicked everyone in it, I put it together and had the vision for the whole thing; it didn't just happen. It was originally set up primarily to perform my songs, although I did encourage everybody else to write songs as much as I possibly could – contrary to what's been said."

He resents the suggestion that he was dictatorial but, as they did in 1981, last summer his fellow Specials stopped working with him again, performing a reunion concert at the Bestival festival on the Isle of Wight in September. Despite the mudbath conditions, Dammers went along to watch. "It sounds like I'm being rude but I was bemused by it and a bit bored because it was so predictable." Asked if he will watch any of the tour, he struggles to find words and sighs, exasperated. "I don't know... well, it's not The Specials, that's a historical fact. I'm always thinking, 'It should have Jerry Dammers in it.'"

As an avowed radical he is disturbed by what he sees as the "extremely conservative" musical approach of his peers and alarmed by their plans to dress in tonic suits made by a company that boasts of the exclusively British origin of its garments. "Is that what The Specials was about? I don't know," he asks rhetorically. They may have had a big skinhead following, but The Specials were a great symbol of racial harmony, and after the first break-up Dammers went on to compose the anti-Apartheid anthem "Free Nelson Mandela".

The Spatial AKA Orchestra perform at London's Barbican centre on 10 March. When he talks about this project, which features Mercury Prize-nominated pianist Zoe Rahman and the acclaimed saxophonists Denys Baptiste and Larry Stabbins, Dammers' mood lightens. "It's just a real honour for me to work with such brilliant musicians," he says. Aside from its remarkable costumes – which liberate the performers from their inhibitions, according to Dammers – the orchestra uses other visual effects including mannequins and video, while mixing funk, ska and jazz with modern British styles such as jungle and dubstep.

Before he finishes talking, Dammers asks me to switch the voice recorder back on to say he still hasn't given up hope of participating in the reunion, even at this late hour. He seems pained that he and Hall have grown so far apart. "Obviously I made loads of mistakes in The Specials. I'm not trying to take all the credit. But Roger Daltrey stuck with Pete Townshend through his development as a human being and I think Terry [Hall] owes me that, given it was my songs that brought him to the attention of the public in the first place."

The other six Specials, he believes, will read this piece. "They will either react against it, or stop and think about what I'm trying to say," he says. "I never give up. Maybe they will have a change of attitude."

The Spatial AKA Orchestra will play the Barbican, London EC2 (020 7638 8891, www.barbican.org.uk), on 10 March