Bernard Mac Laverty is never writing a book that he will admit to. Despite having had nine works published, two of which, Cal and Lamb, were made into films for which he wrote the screenplays, and being shortlisted for last year's Booker Prize for his novel Grace Notes (Virago), the Irish-born, Glasgow-based writer is reluctant to declare a new project much before the final draft. 'You have to be always able to chuck it away,' he says, admitting to a computer replete with unfinished projects unlikely to be subjected to public scrutiny - especially those rejected by his most respected critic and 'important first filter', his wife Madeline. Mac Laverty - whose unusually split surname comes from his Irish roots, he says - compares this state of affairs with a painter's studio, with unfinished canvases propped against the walls. He will say he is working on 'a couple of stories that might make it', one about a man in the snow prompted by a visit to Iowa two years ago during which he experienced minus 29 degree Celsius temperatures. But he is happier talking about his past work, its influences and the creation of the rich imagery that is its hallmark. Although he has lived in Scotland for 12 years, working as a teacher before writing full-time, Mac Laverty says his childhood in Belfast was his biggest influence. 'I am never sure whether it is because it is Ireland or because it is your childhood,' he says. 'But I think a writer does draw on his childhood enormously. 'There was a time when you were about 12 and absorbing everything like blotting paper without being aware of it. 'Now, as a grown man, these kinds of things come back up again.' He recounts numerous examples of events in Grace Notes which were drawn from his own memories, now arising from his fiction to form a train of imagery, rather than his artificially imposing them on his story. For instance, there is the salt cellar with the crease in it because his father tried to open it in a door. The father in Grace Notes has tried just such a trick - and later, his daughter Catherine's partner tries to injure her in much the same way. Catherine is a Scotland-based composer from a Belfast Catholic background whose experience of religion Mac Laverty, a former Catholic, says is similar to his own. She is writing a mass. 'It is a structure within which she can work, but does not believe in.' She loves the trappings of religion, the stained-glass windows, the architecture. Catherine collects shells - empty structures which once contained a living creature - again the links in imagery for which Mac Laverty is acclaimed. Although he chuckles at the journalists who have asked what will happen to Irish writers if peace comes to Ireland - 'What would they have to write about?' - Mac Laverty's adult experience of Belfast, where he worked for 10 years as a medical laboratory technician before going to university at age 28, has, inevitably, cast a shadow over his work. 'I was raised in a time of relative peace, it was just bigotry then and sectarianism, but nobody was getting killed. Then, when I was about 29, they started killing each other and it became very, very serious then. The air was full of hatred.' So Mac Laverty and his wife moved their son and three daughters to Scotland - first to Edinburgh, then to the island of Islay and, recently, Glasgow. It was a move he says was prompted by 'my abhorrence of violence', a theme he returns to repeatedly in his writing. 'There has been a thread of thinking in Ireland of blood sacrifice, of dying for Ireland, and I just hate all of that. It is a kind of nationalism of the worst kind.' Mac Laverty knows this position may not be popular in some quarters - those who 'would say my position is [that of] a kind of wimp or something: 'He is not willing to die for Ireland, to have his boy sent out and shot.' ' Mac Laverty does not rule out returning to Ireland if peace comes. The ideal would be a summer cottage, he says. But for now at least it will be Scotland where this writer who began with 'embarrassing poems' while still at school will continue to produce the rhythmic works he agrees are still poetic - 'poetry in long lines'. Mac Laverty has been called on to read from it all over the world and admits that when he reads from his early work he often changes it to improve the rhythm. He even considered rhyming the two parts of Grace Notes, the first ending in credo, the second in bravo. But he changed his mind, moving the bravo so that Catherine, who opens the book going down (the front steps), could close it going up (to the podium). For although, Mac Laverty says, 'the imagery in my first novel was too schematised, I'm more relaxed about it now', it is that kind of thoughtful precision which has given his work its richness and reputation and which last year ensured that his first novel in 14 years was shortlisted for Britain's top fiction prize.