UK writers' body the Writers' Guild of Great Britain (WGGB) has ruled against musician Dave Stewart's production company in a dispute over credits on his directing debut Honest, which stars Nicole and Natalie Appleton and Melanie Blatt from UK pop group All Saints.

All three WGGB arbitrators ruled in favour of writer Karen Street, saying that she should receive front-billing credit under the terms of her contract with the films' production company, Honest Productions.

"The decision of all three arbitrators was that Karen Street contributed more than 10% of the final script," said the WGGB.

Street has rejected an offer made before the WGGB ruling, proposing that she have a credit as script consultant and for additional writing on the film. "You cannot edit a script that does not exist," Street said.

The company had originally given screen-writing credits to Stewart, Dick Clement and Ian La Frenais on the project, about three gun-toting East End sisters in 1960's swinging London.

Executive producer Keith Northrop commented: "Karen was hired as a script consultant on Honest during the development stage but before Dick Clement and Ian La Frenais became involved. She chose to refer to a WGGB arbitration a dispute about the extent of her contribution to the script. Despite our reservations as to the conduct of the arbitration, we have chosen to accept its determination and have sought, as we have done throughout, to resolve this issue as amicably as possible."

Honest is in the running to appear in a Midnight Screening at next month's Cannes Film Festival. The picture is backed by France's Pandora Cinema, which is handling international sales, and the UK's Pathe Distribution, which is to release the film May 26.