Bremner will be stepping into the shoes of Spud at the 21st birthday celebration of the original Trainspotting film in the old Leith Theatre. The actor will be reading excerpts from a brand new Irvine Welsh novel, which will reveal what has happened to Spud, whose last appearance was in Danny Boyle’s long-awaited Trainspotting sequel T2, when he becomes a writer. The author, who released a novel dedicated the fearsome Trainspotting favourite Begbie last year, has hinted all the characters from the original groundbreaking novel will be making another comeback. Welsh, who will also be reading from the as-yet-unfinished book, will be making his only public appearance of the Edinburgh Festival at Friday’s event, the first major fundraiser for the Leith Theatre Trust, which will feature a screening of the 1996 movie, which also starred Ewan McGregor, Robert Carlyle and Jonny Lee Miller. Iconic post-punk band The Fire Engines is reforming for the five-hour event, which celebrated US record producer and DJ Arthur Baker will also be appearing at. Bremner has signed up as an ambassador for the trust, which has been given a long-term lease by the city council while it draws up plans and raises funds for a full restoration. He said: “As someone who benefited hugely from this city’s great community arts programs - and the guidance of its generous and creative arts workers, I can testify to how powerfully my own horizons were expanded by those experiences and encounters. “The education I received in those venues and community theatre groups fed my mind massively and challenged me to go beyond my own inhibitions - in ways that have been very influential for me and my relationship with my own work today. It was completely invaluable for me. “I know Leith Theatre has great potential to foster and feed the hungry young minds of the city and I wish the trust every success in achieving their fantastic and noble ambitions.” The building, which was reopened temporarily in May for the Hidden Door festival, is hosting the “Trainspotting Turns 21” event, which has been organised by arts collective Neu! Reekie! and Welsh. Rod Stewart, The Proclaimers and Garbage singer Shirley Manson have also backed the campaign to bring the theatre back to life, which Welsh has agreed to spearhead. Bremner added: "Neu! Reekie! And Irvine are true subversives and it's a thrill to be along for the ride on one of their missions. They both love to mess with traditional definitions of Scottish identities, expanding and exploding our wee horizons. That's the kind of work that feeds our culture and forces it into the future. "I won't say anything about what I'll be reading except that it's excellent writing and I'm desperate to read the rest of the book now!" The theatre building was gifted to Leith after its controversial amalgamation with Edinburgh in 1920, but has had a troubled history since opening in 1932. It was badly damaged after being struck by a bomb during the Second World War and was closed for 20 years before it finally reopened in 1961. As well as hosting pop and rock concerts, Leith Theatre would go on to become a mainstay of the Edinburgh International Festival but was eventually closed down in 1988 due to its declining condition.