Ronson and Winehouse performed at the Brit awards this year
Work on a possible James Bond film theme has been abandoned because singer Amy Winehouse is not ready to make music, producer Mark Ronson has said.
The Brit award winner told Sky News that "unless by some miracle of science it gets recorded and someone sings a vocal," the song would not materialise.
Ronson added that their work on other new music had not been finished either.
Winehouse's spokesman said the decision was taken because she had "other ideas" about how the song should be developed.
"She has always made her own decisions about her music. Needless to say, this is part of the process between artist and producer and we're sure they will continue to make great music together," he added.
The pair had yet to be officially signed up to compose the theme for Quantum of Solace, while Ronson said in a recent interview that the singer had been approached to work on the project.
He added that a demo had been produced, which "sounds like a James Bond theme".
Ronson said that they were probably in competition with "loads more really famous people" to write the song, but hoped they would have a chance to write the next one if they were unsuccessful.
Winehouse, whose battle against drink and drug addiction has overshadowed her musical success, recently received a police caution for common assault after slapping a man.