Australia's priciest-ever electoral advertising campaign kicks off this week with the two major contestants (the Liberal Party and the Labor Party, politically approximating to the US Republican and Democratic parties) each spending up to A$20 million ($14.08m; €11.71m; £7.86m) over the next six weeks.

In each case the split is likely to be 75%-25% between mass media and direct mail. TV is expected to account for sixty per cent of each party's budget.

It could be a dirtier-than-usual contest. Both sides concede it could be marked by more increasingly overt attacks on the other party's credibility, following changes to the way political advertising is regulated.

Stephen Smith, immigration minister and campaign spokesman for the opposition Labor Party, defended its right to focus on the government's shortcomings. "Whether it's regrettable or otherwise, the modern political campaign is a mixture of positive and negative," he said.

Labor was at a disadvantage because the Liberal Party has already begun promoting itself through government advertising, Smith alleges. "The Liberal Party has been the beneficiary of over $60 million worth of taxpayer dollars since April-May, which we regard as highly political."

According to media buyers, the Howard administration has poured more than A$100 million into taxpayer-funded political ads over the last twelve months, focusing on Medicare, the enhanced family payments scheme, the environment and regional telecommunications.

Data sourced from: Sydney Morning Herald; additional content by WARC staff