Party girl Lindsay Lohan's been forced to call off her 21st birthday bash on 2 July at Pure nightclub in Las Vegas.

Lindsay, 20, who is currently undergoing a stint in Promises rehab centre in Malibu, wants to be sure she gets her health back instead.

Lindsay will not be having the birthday party at Pure and is focusing on her recovery 100 per cent,' says her spokesperson.

The Mean Girl checked into rehab for the second time this year after she was arrested for a DUI offence last month.