The Cherries have already rejected a loan offer from the French club for the winger, but they are expected to return with a new bid.
Gradel failed to cement a spot in Eddie Howe's first-team last season and he is reluctant to face a similar scenario this season.
And now, according to L'Equipe, circumstances have escalated as the Ivorian has told Bournemouth he wants to join Toulouse.
The 29-year-old has also attracted interest from Hull City, Sunderland and Watford but it is reported his preference is a move to France.