Republican John McCain has a final chance to debate his way back into contention for the American presidency, when he faces rival Barack Obama in New York today (midday AEDT).
McCain is lagging in the polls as the US weathers its worst financial crisis since the Great Depression.
And critics say he should address the economy issues, instead of attacking Obama in the debate.
Senior McCain adviser Nicolle Wallace told NBC television today: "We've never been interested in negative attacks for the purpose of negative attacks. But the truth has to stand on its own tonight."
A Washington Post-ABC News survey has found one-third of voters had a better opinion of Obama after the first two debates, while a quarter thought worse of McCain.
A New York Times-CBS News poll late yesterday had Obama ahead of McCain by the huge margin of 14 points, 53 to 39 per cent, compared to a lead of just three points before last week's second presidential debate.
LIVENEWS.com.au will bring you video coverage and full reaction from the debate from midday today.