2019 Australia election: 10 things to know about the poll

Scott Morrison is Australia's current prime minister

Australians are voting in a closely-fought general election on Saturday.

The poll will decide whether the conservative Liberal-National Coalition wins a third term or is replaced by a Labor administration led by Bill Shorten.

All 151 seats in the House of Representatives will be contested, and half of the 76 seats in the Senate.

The election has been hotly contested in several areas, particularly climate change and the economy.

Prime Minister Scott Morrison told voters in his last pitch on Thursday: "Now is the time to get on and keep on with the work of building our economy, by backing in the choices Australians are wanting to make every day."

Meanwhile, Mr Shorten highlighted climate change and urged voters to push for change.

"Vote for the new vision - the new stability, the new determination of a new Labor Government."

Here are some key things to know about the vote.

1. Voting in the election is compulsory

Unlike many other global democracies, Australia has mandatory voting for people aged 18 and over - or they risk a fine.

This year has seen a record 96.8% enrolment rate. In contrast, the most recent recent US and UK elections drew an estimated 55% and 69% respectively.

Advocates say the mandatory system depolarises the vote and reduces the influence of lobby groups, though critics dispute this.

Voting has also been open for three weeks already. More than four million people, about a quarter of voters, have already cast their ballot at "pre-polling" booths.

• The vote that spans outback to Antarctica

2. Leadership 'madness' may haunt the government

Mr Morrison only became prime minister last August, after bitter party infighting ousted his predecessor, Malcolm Turnbull.

In doing so, Mr Morrison became Australia's fifth leader since 2013.

"It was a peculiarly Australian form of madness," Mr Turnbull told the BBC in March, speaking about a coup culture which began with Labor in 2010.

It's likely to harm the government's standing with voters, predicts Prof Sally Young, a politics expert from the University of Melbourne.

"They're sick of the sniping and undermining," she says. "Knifing a leader - it never goes down well."

3. Climate change is a hot issue

Australia has just endured a year of extreme weather events, including destructive floods, bushfires, cyclones and a severe drought. The past summer was the nation's hottest on record.

It has made climate change a key election issue in some seats, experts say.

Extreme weather has pushed climate change into voters' minds, experts say

Last year, the government scrapped plans to set an emissions reduction target in legislation - prompting fierce criticism.

"Australia's lack of action [on climate change] internationally is becoming more recognised within this country," says Prof Young.

The University of Sydney's Prof Marc Stears agrees, but says it's unclear how widely it will affect voting decisions.

• The big climate call coming to Australia

• How Australia's heat might be here to stay

4. In many ways, the main battle lines are familiar

The major parties have been talking up their traditional strengths. That's subjects like jobs and tax relief for the government, and health and education for Labor.

They will compete fiercely on economic issues, with both parties promising policies aimed at reducing the cost of living,

Bill Shorten has led the Labor opposition for six years

Although Australia's economy is the envy of many countries, wages growth is flat, and there is a generational split in attitudes to house prices.

• How Australia is changing - in 11 charts

5. It's all about the north-south divide

Mr Morrison is overseeing a minority government, meaning he can ill afford to lose support anywhere in the country.

Political observers say he faces challenges from the left and right - a debate that is often framed in geographical terms.

In the northern state of Queensland, experts say the government fears losing votes to more socially conservative minor parties and independents.

But in Victoria in the south, the electorate is perceived as more progressive. It delivered a resounding victory to Labor in a state election five months ago.

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6. The migration debate is absent

During past elections, Australia's major parties have employed tough rhetoric on immigration issues - particularly regarding asylum seekers.

It has often been used to appear strong on issues such as national security, says Prof Stears.

Australia holds asylum seekers in offshore detention, under a controversial bipartisan policy

That debate resurfaced in February, however it appears that the New Zealand mosque attacks in March may have silenced any dog-whistling rhetoric.

• Why Australia's PM is talking of dark threats and 'evil'

7. There are signs of support for minor parties

Prof Young says there is some public cynicism about the major parties, pointing to possible increases in support for other candidates.

High-profile independent candidates have entered key races, and in New South Wales, a recent state election saw rises in minor party support in rural electorates.

8. Is there a risk of foreign interference?

In February, Mr Morrison said a "state actor" had carried out a cyber attack on the parliament and political parties.

Authorities said there was no evidence of electoral interference, but security experts have urged vigilance.

Concerns about alleged foreign interference prompted Australia to introduce new laws last year.

9. Citizenship checks should be water-tight

In 2017, several MPs were disqualified for unintentionally breaking a rule that lawmakers cannot be dual citizens when elected.

Fifteen parliamentarians were ousted, though six later managed to return after relinquishing their non-Australian citizenships.

The saga sparked comprehensive checks of MPs' statuses.

• The story of Australia's dual citizenship crisis

10. What do the opinion polls say?

Opinion polls have narrowed in recent weeks, but Labor still has the edge on a two-party preferred basis.

However, those measures also say that Mr Morrison leads Mr Shorten as preferred prime minister.