With just over four months to go before the federal election, Australians have switched off, with more than a third having little or no interest in September's election. A national survey by Melbourne University also found most Australians believe the quality of leadership and the tone of debate is worse than usual. And 70 per cent lack confidence in the federal government, including almost half of Labor voters.

The results are part of a survey of 1000 voters undertaken by the university's Centre for Advancing Journalism. It reveals a deeper disengagement with politics than usual and presents a challenge for political parties vying for public attention. The centre's senior research fellow, Dr Denis Muller, said the survey found that Australians were ''pretty appalled'' at the standard of politics.

Voter engagement is flagging.

''We're disgusted with the way they [politicians] talk to each other and we think there's a lack of political leadership, so we'll just switch off and vote when the day comes,'' he said. The survey, undertaken in March and April, found:

■ 57 per cent of voters say the quality of political debate is ''noticeably worse'' than the past, with little difference between Labor and Liberal voters.