Britney Spears plans a comeback to surprise fans

Britney Spears' new single could debut next week.

The new track is not the recently leaked ballad, 'Baby Boy', but an up-tempo dance track called 'Gimme More' produced by Timbaland protege Nate 'Danjahandz' Hills.

  Britney Spears on the Sep.issue of Allure magazine

A source, who claims the song will be released in September, said: "People are going to love this new track. It is a whole new funky dance sound." 'Gimme More' was the reported working title of the music video Britney filmed in July. Another source who has heard the track said: "This is going to be a huge hit. Britney will come back with a bang."

Insiders say Britney already has "more than enough material" for her fifth studio album, and is planning to surprise fans with a comeback by releasing it this autumn with no promotional build-up.

Britney - who is currently facing a bitter custody battle with ex-husband Kevin Federline for sons Sean Preston, 23-months, and Jayden James, 11-months - also worked with other producers, including J.R. Rotem, on her new material.

A third source revealed: "The album still has no official title or release date and is being kept top-secret. But Britney is planning to shock everyone by letting it hit the shelves this autumn."