Support for Australian Prime Minister Malcolm Turnbull is at its lowest level since his election last year, according to an opinion poll on Tuesday, fueling speculation of more political upheaval in a country that has seen four leaders in six years.

The Australian newspaper poll showed Turnbull's net satisfaction rating, which measures the difference between those who are satisfied and those who are dissatisfied, had fallen to 29 points, some 11 points lower than after his July 2 election.

Turnbull enjoys only marginal more support from the electorate than Australia's previous prime minister, Tony Abbott, whom he toppled in a party room coup a year ago due to poor voter support.