The troubled singer was set to leave Malibu's Promises rehab centre at the end of next week after completing the full treatment.

But a report in today's Sun newspaper confirms that Britney is to leave two days early, in a bid to attend Kevin Federline's 29th birthday bash at the Eleven nightclub in LA.

"Bosses would have liked her to stay longer" said a source at the Promises centre.

Spears is also hoping to see her sons, Sean and Jayden, at the party.

Though her family and friends are concerned that her treatment has not been finished, Britney has reportedly told them that she feels well enough to go.