Republicans are accused of scaring off voters as Bush looks for converts in Ohio

As George Bush brought his campaign for the "discerning Democrat" to Ohio yesterday, a dispute grew fiercer still over alleged voter fraud and intimidation on polling day, and over thousands of possibly decisive provisional ballots, that will only be certified after the rest of the vote has been counted.

After an early morning stop in neighbouring Pennsylvania, the President arrived in Youngstown, a classic rustbelt town that is normally a Democratic stronghold. But buoyed by the defection to his cause of the city's Democratic mayor, Mr Bush was hoping to garner extra votes that could prove decisive in arguably the most contested of battleground states.

With just five days to go until the vote, the majority of recent polls suggest the President has a narrow lead nationally but that in Ohio - which he carried by a 50/46 margin over Al Gore - Democratic challenger John Kerry has pulled level, or even marginally ahead.

With its 20 electoral college votes, the state is one of the "Big Three" along with Florida and Pennsylvania which may settle the result on 2 November. No Republican has ever won the White House without carrying Ohio and Mr Bush has visited Ohio more than 20 times this year - and will be here several more times before the campaign is over.

This week, on yet another swing through Minnesota, Wisconsin and Iowa - a trio of upper midwestern states he hopes to capture from the Democrats next Tuesday - the President wheeled out the latest version of his stump speech.

It lashes Mr Kerry as a weak and indecisive leader, addicted to second-guessing and incapable of keeping the country safe from terrorist attack.

The familiar mixture of charm, swagger and certainty has been on display as the President bends facts to suit his purpose, and woos waverers by charging Mr Kerry "is not worthy of the traditions of Franklin Roosevelt, Harry Truman and John Kennedy," - Democratic Presidents who knew how to defend the US in time of crisis, according to Mr Bush.

All the while he has assiduously kept away from the issue of the 380 tons of high explosive missing in Iraq, which Democrats are trying to turn into a major issue. At a rally in Iowa, he ignored questions on the subject, repeating the usual mantra that the world was a better place without Saddam Hussein.

"My opponent has no plan, no vision - just a long list of complaints," Mr Bush declared. "But a Monday morning quarterback has never won any game," he added, referring to next-day critics of the tactics used in the Sunday schedule of NFL football games.

But in this contested state, even the virtually daily visits by candidates and celebrities in their corner are being overshadowed by the dispute over voter fraud and intimidation, which has many fearing Ohio may well be the 2004 version of Florida four years ago.

"A storm is brewing in Ohio," Michael Coleman, the Democratic mayor of Columbus, warned. The looming trouble has two components - whether some people on the electoral rolls are in fact entitled to vote, and whether those who are not should nonetheless be allowed to cast a provisional ballot.

The first category is a result of the voter registration drive mounted by Democrats among young and black people in particular. Huge numbers of new voters are on the rolls - a potential pool of support that could make the difference in a state where Mr Bush's margin was just 170,000 votes in 2000, and may be even smaller this time.

Taking advantage of state laws, Republicans have challenged 35,000 names in Ohio, almost half of them in Cuyahoga County, which covers the heavily black and Democratic neighbourhoods of Cleveland, Ohio's second largest city.

Republican officials have also recruited 3,600 election monitors who will be positioned outside polling stations to demand checks on the credentials of suspected ineligible voters. Democrats claim the tactic will create endless lines at the stations, intimidating some voters and making others feel that the wait is simply not worth it.

In an extraordinary move, but in compliance with state laws, Cuyahoga county's election board will hold mass hearings at the Cleveland convention centre to examine the cases of some 9,000 people whose registration has been challenged by the Ohio Republican party. Republicans deny they are deliberately attempting to scare away Democrats and hold down turnout. "we just don't know if the registrations are valid, this is just part of the normal process," one local Republican said yesterday.

Equally, confusion surrounds the provisional ballots, to be cast by voters whose names are not on their precinct rolls but who say they have been incorrectly omitted. After a court wrangle, it has been decided that such people will be able to vote - but their ballots will only be counted later, once their credentials have been verified.

That means that if the result in Ohio is really close, the winner in the state and - who knows - of the Presidential election as a whole may not be known until days, perhaps weeks, after 2 November. "I'm praying that we have a clear victor on election night, I don't care who, because otherwise we could have an election that could make Florida 2000 look like a picnic," said Curtis Gans, director of the nonpartisan Committee for the Study of the American Electorate.

That was precisely what Mr Bush was hoping to achieve with his stop in Youngstown, a Democratic stronghold where, if party support dips below 65 per cent, a Democratic candidate is likely to be in state-wide trouble. At his side was likely to be George McKelvey, Youngstown's outgoing mayor, converted by Mr Bush's stance on protective steel tariffs and the war against terror (though the tariffs have since been scrapped after huge international complaint).

"What have we got for delivering 70 per cent of our vote over the past century to Democratic presidential candidates?" Mr McKelvey asked, when announcing his backing for the President's two months ago. "Dare I speak the answer? Nothing! The strong Democratic vote in [Youngstown's] Mahoning Valley is taken for granted."

Even by this year's exceptionally extravagant standards, colossal sums have been spent to win the support of battle weary Ohio voters. The western industrial city of Toledo has seen more political TV ads per capita than any other television market in the country. In 2004, the Cleveland market alone has carried $40m worth of ads.