Gossip Girl stars Blake Lively and Penn Badgley have backed U.S. presidential hopeful Barack Obama - with Lively urging people to contact her if they ever consider voting for rival John McCain.

The pair appear in a 30-second online film to support Democrat politician Obama - and jokingly warn against the dangers of voting for Republican McCain.

In the short ad Lively says, "If you're ever out somewhere and you're considering voting McCain, just call me. I'll pick you up. No questions asked." And Penn holds up a John McCain emblazoned baseball cap and declares, "Mom, Dad, I found this in your room" before encouraging youngsters to "talk to your parents about John McCain".

The commercial, directed by Mr and Mrs Smith director Doug Limon, is part of Move On's Youth Vote program and will air during a Gossip Girl ad break on American network CW, and on stations MTV and Comedy Central. (CL/WNWCPL/ZN)

Copyright 2008 WENN