Washington, Oct 1: Democratic vice presidential nominee Joe Biden and his rival Sarah Palin are training hard and not taking anything for granted before the only vice presidential debate of 2008 on Thursday.

The veep debate at Washington University in St. Louis is expected to center on domestic and foreign policy, and the list of topics could run the gamut, FOX News reported.

So both running mates are hunkering down for intensive rehearsal sessions with campaign aides. Each candidate will step onto the stage with a distinct set of challenges.

Palin, under fire from liberals and conservatives alike for her recent interview performances, faces questions about her experience and ability to make the meteoric leap from first-term Alaska Governor to “a heartbeat away.”

Biden, persistently teased, as one columnist put it, for tickling “the back of his throat with his toes,” is tasked with showing restraint as well as demonstrating his economic acumen -- as the campaign dialogue shifts away from his perceived strong suit of foreign policy and toward the financial crisis.

Biden was in Wilmington, Del., rehearsing for his second day in a row, Palin stepped off the campaign trail for two days of sequestered debate preparation at John McCain's ranch in Sedona.

Senior McCain advisers, including Steve Schmidt and Mark Wallace, as well as McCain’s wife Cindy, surrounded palin.

One Palin aide told FOX Tuesday that she was rehearsing outside by a creek on the McCain ranch.

Pressure is mounting on Palin to deliver a strong performance, to follow up her rousing GOP convention speech in early September and make up for the relatively few media interviews she's granted since. (ANI)