SYDNEY — An angry advertising campaign over a proposed super-tax is pushing usually placid Australian voters toward one of the closest, most divisive elections in memory.

Annoyed that the world's biggest mining companies are attacking his plans to extract a 40 percent tax on the profits of mineral exports, Prime Minister Kevin Rudd has opened a costly, new-style campaign to regain public support that has been badly dented by a series of humiliations.

But voters already are turning off Canberra's pre-election clashes. The latest voter survey by the respected Newspoll shows support for the Australian Greens has surged to a record high as voters turn away from both Labor and the opposition conservative coalition of Liberal-National parties.