BEIJING, July 25 -- Sienna Miller, Madonna and Leonardo DiCaprio will battle it out to be named the ultimate green celebrity. Playhouse Disney's Playing for the Planet Awards has announced a shortlist of 10 stars who have been nominated for the Greenest Star prize for using their fame to promote environmental issues.

Sienna has been recognised for her work in raising awareness about global warming, while Leonardo is a tireless campaigner and donator to various green campaigns.

Singer Madonna arrives at amfAR's Cinema Against AIDS 2008 event in Mougins during the 61th Cannes Film Festival May 22, 2008.

"The Departed" actor recently made a documentary "The 11th Hour" about global warming.

Other contenders include British supermodel Lily Cole, who only works with environmentally friendly companies, and "Harry Potter" actress Emma Watson, who has spent time working with the Wild Trout Trust.

Celebrity power couple Gwyneth Paltrow and husband Chris Martin also received a nomination.

"The Iron Man" actress has been the face of U.S. environmental campaigns to cut down the use of oil, while her Coldplay rocker spouse travels on an eco-friendly tour bus complete with recycling facilities.

Johnny Depp, designer Stella McCartney, Smile singer Lily Allen and British actor David Tennant have also made the shortlist.