Troubled pop star Britney Spears has pulled out of recording a duet with former lover Justin Timberlake, according to reports. The Toxic hitmaker was scheduled to reunite with her old flame to produce a comeback track produced by Timbaland, but ditched the idea at the last minute. A source tells New York gossip column, PageSix, "Timbaland set aside a week out of his crazy schedule to do this - and then, just before she was supposed to fly out, Britney abruptly canceled the session and refused to do the song. "It's crazy. She's looking for a comeback, and this would have not only been a huge hit, but something she could have opened the MTV Video Awards with and really blown everyone away." The cancellation has now stalled Spears' comeback ambitions and has sparked rumours she might be dropped her label Jive. Another source tells PageSix, "Listen, everyone is worried. In her mind, her album is done and she's done enough work. "People at Jive have been with Britney since album one, and have an investment in her. They have faith that once the material is there, she will become focused and step it up. She's very competitive, but at the end of the day, it's hard. She has to do the work - no one can do it for her." Representatives for Spears, Timberlake and Jive declined to comment.