Britney Spears is reportedly to release a new Paris Hilton sex tape unless the socialite starts behaving in a more friendly manner towards Britney and her entourage.

The former partying best friends were reportedly spotted arguing at Britney’s 26th birthday celebrations last weekend after Britney felt Paris was hogging the spotlight - but now a source has claimed there is a bigger beef between the two.

A source told the Sun that Britney is sick of Paris mocking and being rude to her friends and is prepared to blackmail the heiress into behaving better around them.

The source claims that Britney has sent Paris a letter, explaining that she will release video footage of Paris in bed with another woman: “The letter warns Paris that if she continues being rude to people, the footage will be leaked online.”

But Queen of the Hollywood partying scene Paris isn’t bothered by the threat: “Paris laughed when she got the letter and said it was crap. It’s obvious Britney and her bratty pals are being silly.”