BAD TEACHER (15, 92 mins) Comedy/Romance. Cameron Diaz, Jason Segel, Justin Timberlake, Lucy Punch, John Michael Higgins, Phyllis Smith, Dave 'Gruber' Allen. Director: Jake Kasdan.

Released: June 17 (UK & Ireland) One inspirational man or woman can make a difference... in the classroom.

Robert Donat won the hearts and minds of his young charges as he bade a tearful goodbye to Mr Chips, then Sidney Poitier brought hope back to the unruly streets of the East End of London in To Sir, With Love.

Glenn Ford clashed with the rebellious students at an inner city school in Blackboard Jungle, while Robin Williams roused his private school boys to their feet to cheer, "O Captain, My Captain" at the conclusion of Dead Poets Society.

Three cheers for teachers willing to buck the system and put their wayward charges before a stuffy curriculum, regardless of how unpopular it might make them with the staffroom.

Jake Kasdan's foul-mouthed comedy won't be winning a gold star alongside those classic school days yarns.

Bad Teacher witnesses the devastation wrought by a hard-drinking, money-grabbing harlot, who is granted an opportunity to mould the impressionable minds of today's alienated youth.

She schemes, plots and blackmails her way to stunning grades, destroying anyone who dares to stand in her path.

It's a morality tale for our fame- and power-driven times: succeed at all costs.

Alas, effort counts for nothing without a modicum of intelligence and wit, and Gene Stupnitsky and Lee Eisenberg's gleefully un-PC script is a clutter of mean-spirited barbs and innuendo that leave us to wonder if we're in detention and Kasdan's film is the punishment.

Elizabeth Halsey (Cameron Diaz) is a booze-addled wreck, draining her drippy, rich boyfriend dry until he finally musters the courage to dump her... with mummy beside him for support.

So she reluctantly returns to her teaching job at a high school run by Principal Wally Snur (John Michael Higgins).

Rebuffing the advances of oafish PE master Russell Gettis (Jason Segel), Elizabeth sets her sights on handsome new teacher Scott Delacorte (Justin Timberlake), who has an expensive watch on his wrist.

Unthinkably, Scott resists her flirtations and begins a tender romance with the school's prim and proper teacher, Amy Squirrel (Lucy Punch).

Elizabeth is used to getting her own way and she declares war on Amy, by fair means or - preferably - foul.

Bad Teacher is a nice idea poorly executed, underpinned by a script with too few laughs and a central heroine whose selfish escapades leave us without a single drop of sympathy or affection for Elizabeth.

Diaz is a gifted comic actress but she is on a hiding to nothing here, never quite hitting the target with the lacklustre one-liners.

Punch is more appealing as the victim of Elizabeth's cruelty while Segel and Timberlake vie for their leading lady's affections, the latter poking fun at his Trousersnake tag in the film's obligatory gross-out moment.

RATING: 5/10