Kerry edges into precarious lead

The US election was thrown wide open today as a leading poll put John Kerry ahead for the first time.

In a dramatic shift, George Bush has been overtaken by a single percentage point, according to the ABC/Washington Post tracking survey.

It put Mr Kerry on 49 per cent, with President Bush down one point to 48 per cent - an exact reversal of their standing yesterday.

Most election polls show the President keeping his lead by an average of 2.8 points but the ABC/Post poll is considered one of the most authoritative and has consistently shown Mr Kerry slowly catching up.

The survey was completed before Bill Clinton attracted a crowd of tens of thousands to support the Kerry campaign in Philadelphia, which is likely to produce another boost for the challenger.

The polls suggest beating terrorism - Mr Bush's strongest issue - has slipped as the most important issue for voters, from 28 to 20 per cent. Now the economy and jobs is seen as the biggest issue, by 24 per cent of the electorate.

In a nailbitingly tight contest, the President has slender leads in the two hardest- fought states, Florida and Ohio, of one per cent and 0.8 per cent. Analysts say Mr Kerry needs to crack open at least one of these to win.

Mr Bush also holds narrow leads in Iowa, Wisconsin, Minnesota and New Mexico - which could deliver the President the electoral college votes to claim a second term, even if he loses a bigger state.

The closeness of the finish in the swing states has fuelled fears of another split result, in which Mr Bush could win the contest but fail to poll a clear majority of votes cast.