Michael Phelps stars in White House Barney Cam

(AFP/Getty Images)

Olympic gold medalists Michael Phelps and Nastia Liukin guest star in the final holiday Barney the dog video from the White House.

In the "Barney Cam" Christmas greeting, the first family's Scottish terrier scampers amid the White House's red, white and blue holiday decorations before retiring for a nap and imagining himself as an athlete.

Barney is shown in cutout animation as an Olympic vaulter, swimmer and synchronised diver with fellow terrier Miss Beazley, both in red swimsuits. He also dreams of sinking the final putt to secure the Ryder Cup, with the entire US Ryder Cup team chanting "Barney, Barney, Barney!"

The Barney Cam was an instant holiday hit when it was introduced in 2002 and got 24 million web visitors on its first day. Since then, Barney's holiday videos have featured former PM Tony Blair, Bush adviser Karl Rove, country singers Dolly Parton and Alan Jackson and other stars.

The videos aren't Barney's only star turn, though. He was an inadvertent hit on YouTube recently when he was taped biting a reporter who tried to get his attention.

The Barney Cam spot introduced yesterday starts with President George W. Bush, his wife, Laura, and their daughters, Jenna and Barbara, reminiscing about their times together in the White House, then sending Barney off to decorate and nap.

After a wake-up from President Bush ("We're sprinting to the finish, not napping to the finish"), Barney gets a "10" score from Liukin and fellow gymnast Shawn Johnson.

Phelps tells Barney: "I'm glad the decorations are finally coming together and you're using my favorite colour, gold."