Legal battles have already broken out in many states, including battleground states Iowa, Ohio and Florida, as Republicans and Democrats turned to the courts to determine voter eligibility, electronic voting and handling of absentee and provisional ballots.

Two federal judges have ruled that representatives from US political parties were barred from appearing at polling places in the Midwestern state of Ohio and questioning voters’ right to cast ballots.

The rulings came in response to lawsuits filed by a black couple and Democratic Party officials.

The Republican Party said it would appeal.

In Florida, which could be pivotal in determining whether the Republican president will remain in the White House, civic rights groups warned that legal challenges could again delay the outcome of the presidential election for weeks if the race was as close as opinion polls suggested.

“There is an election emergency occurring in Florida as we speak because authorities in Broward, one of the counties in the state, have failed to send out nearly 60,000 absentee ballots,” Grace Ali, spokeswoman for the Lawyers Committee for Civil Rights Under Law, said.

The 2000 presidential election turned to catastrophe when the results in the decisive state of Florida were contested and held in limbo for 36 days of recounts and litigation.

The US Supreme Court finally made a ruling that halted the recount and effectively declared Bush the winner over Democrat candidate Al Gore.

President George W Bush’s Republican party vowed today it would match or even outnumber the 10,000 lawyers monitoring battleground states for Democratic challenger Senator John Kerry on election day tomorrow.

“When the other side says they’re going to have 10,000 lawyers on the ground, we went out and got some for ourselves,” Republican party chairman Ed Gillespie said.

Not taking any chances this time, the US Justice Department has announced it will send more than 1,000 federal election observers into 25 states, three times as many poll watchers on election day four years ago.

Independent legal and civil rights groups have also recruited their own volunteers and set up hotlines to help voters.

The Election Protection Coalition, comprising 60 groups to protect voter’s rights, has received more than 50,000 calls since it opened hotlines in mid-October.

It has set up 21 call centres across the country manned by 8,000 lawyers and legal volunteers, said Ali, whose committee is a key component of the coalition.

The Centre For Voting and Democracy, another independent and non-profit group helping to monitor elections, charged that tens of thousands of people were on the voting rolls of more than one state.