WASHINGTON: With less than a week to go before polling day in America's Congressional elections, voters continue to be blitzed on TV, in the mail and over the phone by the most negative political advertising campaign in US history.

According to Professor Ray Seidelman at New York State's Sarah Lawrence College, who specialises in political advertising and voter turnout, the two warring parties have so far spent almost $160 million (€125,26m; £83.84m) on ads that specifically attack a political opponent.

Conversely, just $17m has been spent by Republicans and Democrats in portraying positive images of their own candidates and parties.

This, says Seidelman, boils down to the message: "Don't vote for a candidate; vote against the opponent." Or as the Washington Post more pithily put it: "That's nearly $1 of nice for every $10 of nasty."

A campaign finance law enacted in 2002 allows such negative advertising only if it is 'independent expenditure', for example when the parties (or other vested interests) do not directly coordinate with the candidates they support.

Data compiled by the Federal Election Commission shows that such negative (alright, dirty) campaigning is already 54% higher than in the same period in the 2004 election season.

By the start of this week, Republicans had spent $87.5m and Democrats $72.6m specifically to oppose each other's candidates. But the edge on negativity, according to independent analyses of the ads, goes to the GOP ('gallant old party', a term coined of the Republican Party in 1875).

An especially negative example - now withdrawn - was an ad in Tennessee targeting black Democratic Senate candidate Harold Ford and featuring a blonde with a come-hither look. Financed by the Republican National Committee, the ad was widely denounced as pandering to racism because it implied that Ford dated white women.

But that's subtlety personified compared with another ad from the same source, this time in Indiana, which fingered Democrat Baron Hill, madmouthing his voting and advocacy support for such issues as banning the sale of violent and sexually explicit video games to teens and the use of federal money to pay for abortion-related costs.

Comments Seidelman: "Negative ads only work in two situations - when you are incredibly desperate or when you're incredibly close to the end."

"[But] it works only in the narrow sense. In the long run what it does is create a tremendous amount of distrust in the process."

Given that feculent politics and sex are often intertwined, perhaps the last word should rest with Woody Allen: "Is sex dirty? Only if it's done right."

Data sourced from Washington Post Online; additional content by WARC staff