Britney Spears has spoken out against a two-hour biopic about her life

Britney Spears is not involved with the film about her, and doesn't want to be. Photo / Supplied

Britney Spears has slammed the upcoming movie about her life.

The 34-year-old singer will be the focus of a new two-hour biopic from Lifetime, which will detail her career and troubled personal life but Britney has insisted that she has not approved it.

Her rep told Us Weekly: "Britney Spears will not be contributing in any way, shape or form to the Lifetime biopic, nor does it have her blessing."

The movie, which will be called Britney, will star Natasha Bassett in the title role and is set to tell the "tumultuous true story" of her life, according to The Hollywood Reporter.

Britney's relationship with Justin Timberlake, her brief marriage to childhood friend Jason Alexander, divorce from Kevin Federline, the father of her two sons - Sean, 10, and Jayden, nine - and broken engagement with Jason Trawick, are all expected to be examined in the movie.

Production will begin in Vancouver on September 17th and the movie is set to air next year.