Australia's opposition Labour party is on course to win power at this weekend's national election, a widely watched poll showed on Thursday, as conservative Prime Minister Scott Morrison (above) fails to woo voters with his promise of economic stability.

An Essential Poll for The Guardian newspaper showed Labour ahead of Morrison's coalition government by a margin of 51.5-48.5 on a two-party preferred basis where votes are distributed until a winner is declared.

The poll is one of the last barometers of Morrison's standing with voters, who have largely been unswayed by his campaign message that Labour would damage Australia's economy, which has recorded 28 years of consecutive growth.

Morrison has centred his campaign on his government's projection to deliver Australia's first budget surplus in more than 10 years.

Labour, which lost the last two elections in 2013 and 2016, has promised to match the government's 2019-20 surplus and then deliver a bigger surplus in 2020-21.

Labour leader Bill Shorten has also appealed to disillusioned voters, both young and old, promising to make the country's taxation system fairer and to fight climate change.

Morrison and Shorten will deliver speeches on Thursday in last-minute pitches to undecided voters.

The speeches come as the Australian Financial Review newspaper endorsed Morrison, joining nearly all of the country's largest newspapers in supporting the conservative prime minister.

- Reuters