The Washington Post/ABC poll gave Democrat Obama a 52 per cent to 43 per cent lead over his Republican rival, one of the few occasions when he has cracked the 50 per cent barrier in the campaign leading up to the November 4 election.

Just two weeks ago, before the crisis really took hold, the Democrat had a slim two-point lead with the race a statistical dead-heat.

Mr Obama also opened a 53 per cent to 39 per cent gap over Mr McCain on who voters trust most to handle the economy in the ABC News/Washington Post survey.

The McCain campaign however rejected the poll as an outlier which failed to capture relative levels of party identification in what other recent polls have portrayed as a tight race.

But a Fox News Opinion Dynamic also seemed to show evidence of an Obama surge in the polls, putting the Illinois senator up by 45 per cent to 39 per cent, double the three point lead he had held earlier this month.

But another respected survey, the new NBC News/Wall Street Journal poll put the gap at only two points, 48 per cent to 46 per cent, almost unchanged from the snapshot of the race conducted after the party conventions.

The polls came out as new drama consumed the riveting presidential race, as Mr McCain put his campaign on hold to return to Washington and join the effort to pass a US$700 billion (S$996 billion) Wall Street bailout through Congress.

Mr Obama however refused his rival's call to delay Friday's first presidential debate over the crisis.

The ABC poll appeared to suggest that the Wall Street meltdown and economic fears in the heartland were starting to impact the race.

Only nine per cent of those surveyed agreed that US economy was in good or excellent shape, the first time since 1992 that number has been in the single digits, the Post said.

Just 14 per cent said the country is moving in the right direction - the lowest figure since 1973.

Asked who they trust more to handle the economy, 53 per cent chose Mr Obama and 39 per cent, Mr McCain.

In a Los Angeles Times/Bloomberg poll also published on Wednesday, 48 perc ent of respondents said Mr Obama could do a better job handling the financial crisis, and 35 per cent said Mr McCain could.

Mr McCain's veteran pollster Bill McInturff dismissed the Post poll as a rogue reading that failed to capture relative levels of party identification among voters, which he said matched other polls suggesting a much tighter race.

'It's just easy to say, politely, that this one poll is an unusual outlier that does not represent where this campaign is nor where it's headed in the next day or two before we get to the first debate,' he said on a conference call.

A National Public Radio poll meanwhile gave Mr McCain the edge, putting him up two points on Mr Obama in 14 battleground states, where Mr Obama had led by three points in August.

In a Rasmussen daily tracking poll on Wednesday, Mr Obama led Mr McCain by just two points 49 per cent to 47 per cent. In Wednesday's Gallup Daily poll the Democrat led by 47 per cent to 44 per cent, unchanged from Tuesday.

CNN meanwhile released a sheaf of new battleground polls which appeared to confirm earlier surveys which had Mr Obama in front.

The Illinois senator led 51 per cent to 47 per cent in western Colorado, which both campaigns feel could be a crucial state if the race stays tight.

Mr Obama also led Mr McCain in Michigan, another Republican target and he enjoyed a 53 per cent to 44 per cent edge in Pennsylvania a bellwether which most experts feel Democrats must win if they want to take the White House. -- AFP