Australian Prime Minister Malcolm Turnbull Sunday called an election for both houses of parliament on July 2 as he seeks his own mandate with the public just eight months after deposing predecessor Tony Abbott in a party coup.

The widely expected announcement was the latest chapter in the turbulent world of Australian politics, where a revolving door of leaders saw multi-millionaire former banker Turnbull, 61, become the fourth prime minister in just over two years when he ousted Abbott in September.

‘The governor-general has accepted my advice to dissolve both houses of parliament effective tomorrow morning, and call an election for both houses, a double dissolution, on 2 July,’ Turnbull said at a press conference in Canberra as he announced one of the nation's longest-ever election campaigns.

‘Australians will have a very clear choice -- to keep the course, maintain the commitment to our national economic plan for growth and jobs, or go back to Labour, with its high-taxing, higher spending, debt and deficit agenda.

‘I will be seeking a mandate from the Australian people as the prime minister of this country to carry out this (economic) plan.’

Labour opposition leader Bill Shorten, a 48-year-old ambitious former union chief, is aiming to add his name to the prime ministerial list when he takes on the Liberal Party's Turnbull in what is tipped to be a tightly contested vote.

The latest opinion polls published by News Limited newspapers on Sunday showed the coalition and Labour neck-and-neck at 50-50.

Turnbull ruled out a snap poll after he assumed the top job but stayed true to his threat last month to call early general elections by using the trigger of a double dissolution -- where all seats in both houses of parliament are contested -- after deadlocked legislation failed to pass the upper house Senate.

The suave ex-barrister and journalist, a moderate on social issues who supports gay marriage and making Australia a republic, came into power with high personal ratings.

But support for him and the ruling Liberal-National coalition has slipped over the past few months, according to successive opinion polls, amid poorly handled debates about tax and other reforms and internal party divisions fuelled by discontent from Abbott's conservative supporters.

- 'Not just parties and personalities' -

The coalition has traditionally campaigned on its purported strength in managing the economy, with Turnbull and Treasurer Scott Morrison on Tuesday pledging to pursue an ‘economic plan’ that boosts jobs and growth when they handed down their first national budget.

Labour's pitch is set to focus on the party's traditional policy areas of improving health and education.

‘I will fight this election on schools and education. I will fight this election for health, hospitals and Medicare (public healthcare system). I will fight this election for real action on climate change,’ Shorten told reporters in the southern island state of Tasmania.

‘This election is much more than a choice between parties and personalities. This election is a choice about what sort of Australia that we want to live in.’

Since Labour's Kevin Rudd become prime minister in 2007 after conservative leader John Howard's decade in power, the two parties have played musical chairs with the nation's highest political office.

Rudd was toppled by Julia Gillard -- the country's first female prime minister -- in 2010, before being restored to power in 2013 amid bitter party infighting.

Just a few months later, he lost the elections to Abbott, who was then unseated by Turnbull last year.

Voting is mandatory in Australia for all adults, with turnout never falling below 90 percent since it became compulsory in 1924.