WASHINGTON - JOHN McCain's campaign manager Rick Davis predicted the Republican would pull off a 'slam bang' comeback in Tuesday's election, despite polls which make Barack Obama the overwhelming favorite.

But Mr Obama's Democratic camp argued that its candidate was carving out a formidable advantage as millions of Americans vote early, requiring Mr McCain to carry the day Tuesday by huge margins.

'Look, this election is moving very quickly,' Mr Davis said on Fox News on Sunday.

'There is no doubt that John McCain is increasing his margins in almost every state in the country right now and I think what we're in for is a slam-bang finish.

'I mean, it's going to be wild. I think that we are able to close this campaign, John McCain may be the greatest closer politician of all time.

'He's been counted out before and won these kinds of states, and we're in the process of winning them right now.'

Mr Obama's senior advisor David Axelrod however argued that Mr Davis was deliberately obscuring the true nature of the race to avoid depressing his candidate's turnout.

'I think that he needs to spend some sort of interpretation to keep his troops up,' said Mr Axelrod on ABC's This Week.

'When you're at the end of the campaign and things are tilting against you, that's what you do. I don't think any objective look at the polls would suggest that.

'But the important thing is, people, have been voting for several weeks, about a third of the country will have voted by Tuesday in early voting. And the edge is pretty substantial in our favor.'

The latest Rasmussen daily tracking poll on Sunday showed Mr Obama leading with 51 per cent of the vote with Mr McCain five points back on 46 per cent. In an ominous sign for Mr McCain it was the 38th consecutive day the that Obama was between 50 and 52 per cent of the vote.

Saturday's latest poll of likely voters by Gallup gave Mr Obama a 10 point lead nationally and the Democrat also leads in many of the key battleground states. -- AFP