A bearded Ewan McGregor at the launch

Calling Velvet Goldmine "a trailer" for his own film, he said: "My feeling was that it was based fairly substantially on Ziggy Stardust, and as I intend to do my own version of it, I'd rather not work with a competitive film."

Haynes is happy to admit to Bowie's influence. "It is all over the film - because he made such an indelible mark with his music, his life story and his images."

But classic tracks from Roxy Music, T Rex and Iggy Pop did make it into the film.

Velvet Goldmine did not go down well with critics either when the film was premiered in Edinbrugh during the summer - they found the film a disappointment.

McGregor plays another rock star - who strips on stage - in the movie, and Muriel's Wedding star Toni Collette plays his wife.

The Trainspotting actor sang live for his part as Kurt Wild, but he wasn't afraid of showing off his musical skills during filming.

"You've just got to get up there and do it, and lose yourself," he said.

The film opens across Britain on Friday.