CANBERRA, May 18 (Xinhua) -- Voting has begun in Australia's general election Saturday, with the Opposition "quietly confident" of victory.

According to an opinion poll released by Newspoll on Friday night, the Opposition Australian Labor Party (ALP) leads Prime Minister (PM) Scott Morrison's incumbent Liberal-National Party coalition (LNP) 51.5-48.5 on a two-party preferred basis.

If accurate, it means that the ALP could win power after six years in Opposition.

ALP's leader Bill Shorten has built his campaign on the idea of change. He has promised record investment in healthcare while also increasing funding for education and infrastructure.

Morrison and the LNP, on the other hand, have campaigned on a message of stability; saying that now is not the time for change and that they are the party best-suited to manage the economy.

The major differences in the policies of the two major parties are in their tax proposals and their approach to climate change.

The LNP has promised tax cuts for all working Australians that will cost the budget 300 billion Australian dollars (205.8 billion U.S. dollars) by 2030 while Labor would only implement tax cuts for low-income earners while also closing tax loopholes that benefit the wealthy.

Shorten has pledged to reduce emissions by 45 percent from 2005 levels and have 50 percent of electricity come from renewable sources by 2030 while the LNP has not made any climate commitments beyond Australia's international emissions reduction obligations.

Asked about his prediction for the result on Saturday morning, Shorten said that there was a mood for change among voters.

"I am confident. It's now in the judgment of the people," he said during an appearance on Australian Broadcasting Corporation (ABC) television.

"I am quietly confident that there is a mood to vote for real change.

"Our Labor message from my united team is resonating with people."

Shorten voted in his own Melbourne electorate on Saturday morning before hitting the campaign trail in Victoria for the last time.

Morrison spent Saturday morning touring crucial marginal electorates in Tasmania where he said that he was expecting a "long night" and a close election.

"The system is working, people are voting. We're one of the oldest democracies in the world, this is something we celebrate today," he told Seven Network television.

"I think it will be a long night... it will be a long night of counting. I've always said this election is going to be close.

"(Voters) have a choice between myself and Bill Shorten as prime minister. A government that knows how to manage money and a Labor party that has never proven they know how to manage money."

Voting closes at 6 p. m. local time and counting will begin immediately.

However, the Australian Electoral Commission on Friday night revealed that 4.76 million Australians voted early, up from 3.2 million in 2016.