Who on earth is Martin Hardy?The screenwriter of Michael Winterbottom‘s “Tristram Shandy: A Cock and Bull Story” has received a British Independent Film Award nomination for his inspired adaptation of Laurence Sterne’s rambling 18th century novel. But before his name popped up on the credits of Winterbottom’s movie, he was a complete unknown. Ask the folks at Revolution Films about him, and they mutter evasively that he has written a couple of things before, although the actual titles escape them. On IMDb, he has only one previous credit — as a location coordinator on Michael Palin’s 1992 TV series “Pole to Pole.” There’s a good reason for all this mystery. Martin Hardy — at least, the one who wrote “Tristram Shandy” — doesn’t exist. He’s a fiction invented to cover a split between Winterbottom and the pic’s writer, Frank Cottrell Boyce. Cottrell Boyce took his name off the movie not for the usual reason — that he didn’t like it — but because he’d had enough of being at Winterbottom’s beck and call. He saw removing his credit as a psychological way of ending their long working relationship, stretching back six movies to Winterbottom’s debut “Butterfly Kiss” in 1995. “I just had to move on,” Cottrell Boyce says. “Actually, I think ‘Tristram Shandy’ is the best film he’s made for donkey’s years. What better way to walk away than by giving him a good script for free?” After a decade of screenwriting success, Cottrell Boyce has had something of a career shift in the past couple of years, becoming an equally acclaimed children’s novelist. His first book was actually a rewrite of his own original screenplay for the Danny Boyle movie “Millions.” His second novel, “Framed,” is shortlisted for the Whitbread Prize, one of Blighty’s biggest literary awards. He’s also devoting himself to working with a community arts project in his hometown Liverpool, called Bootle Arts & Action, with which he’s developing a movie for BBC Films about asylum seekers. Meanwhile, Hardy is getting all the glory for finding a way to adapt Sterne’s virtually unfilmable comic masterpiece. There’s something about having a fictional screenwriter that fits perfectly with the playful, self-reflexive spirit both of Sterne’s novel and Winterbottom’s movie. That’s partly why the producers have been trying to keep the joke running by not admitting to the writer’s true identity. The final irony is that Hardy’s rivals for the BIFA script prize, which will be awarded Nov. 30, include none other than Cottrell Boyce himself, nominated for “Millions.” Hollywood waits for Brown The local popularity of Hollywood movies made in Britain is the single biggest reason the U.K. has bucked this year’s worldwide box office slump. Pics such as “Harry Potter and the Goblet of Fire,” “Nanny McPhee,” “Wallace & Gromit,” “Pride & Prejudice,” “Charlie and the Chocolate Factory,” “Batman Begins,” “The Hitchhiker’s Guide to the Galaxy,” and “Closer” have been embraced with disproportionate enthusiasm by British audiences. But the U.S. majors have slashed their spending on British production this year, thanks to the weak dollar and a clampdown on tax breaks. Inward investment in 2005 to date totals $467 million for 18 pics, against $873 million for 15 pics in the same period last year. Note that the number of films has actually increased, but average budgets have shrunk dramatically. That should give U.K. chancellor Gordon Brown some food for thought as he prepares to make his annual pre-budget statement Dec. 5. He is expected to announce the terms of the new production tax credit, due to start in April, and he has been lobbied by the U.S. majors and the British production services sector to improve the deal for movies costing more than $34 million. In his original proposals, the benefit worked out to a paltry 6% or so, but the biz argues 15% is necessary to keep the U.S. studios making blockbusters in Blighty. British cinemagoers evidently want that. But does Brown think it’s worth the cost?