Australian Prime Minister Malcolm Turnbull's personal popularity is at its highest level in two years, an opinion poll showed Monday, but his government still trails the opposition a month before crucial by-elections.

The latest Newspoll, published by The Australian newspaper, gave Turnbull a 40 percent approval rating, the highest since his government was elected in 2016, as support for the far-right One Nation party has slumped.

Bill Shorten, leader of the opposition Labor Party, scored a personal rating of 33 percent.