Major parties confident as minor parties pose threat in Australian election

The leaders of Australia's two largest political parties both remain confident that they will win the Federal Election as polls opened on Saturday.

Incumbent Prime Minister Malcolm Turnbull cast his vote at a local primary school in his seat of Wentworth on the southern shore of Sydney Harbor while Labor Party leader Bill Shorten continued to campaign in Western Sydney.

"There's never been a more exciting time to vote for a stable majority Coalition government," Turnbull said.

Several marginal seats in Sydney's Western suburbs are expected to be crucial to determining if there is a change in government with the coalition desperate to hang on to a small advantage in the seats of Lindsay, Reid and Macarthur.

Shorten said he is confident of a Labor win despite the last polls of the election giving Turnbull's Liberal-National Coalition a slight edge.

"I'm absolutely sure that Labor is closing at the right time. I feel very confident that our message ... is cutting through." Shorten said in Lindsay.

"Labor has worked on a policy agenda for the Australian people. We are ready to govern, we are ready to implement our policy agenda for the Australian people, and we are ready to serve."

Shorten will continue to campaign for most of Saturday before he returns to Melbourne to cast his own vote while Turnbull's campaign is at an end with the prime minister's next public appearance expected to be on Saturday night.

Shorten's deputy opposition leader, Tanya Plibersek, said she is proud of Labor's work as the opposition in the last three years regardless of the election result.

"We are as close today as we were before the 1993 election, the one Paul Keating called the sweetest victory of all," Plibersek said after casting her vote in the safe Labor seat of Sydney on Saturday.

"If we happen to win today after all our hard work after putting out our 100 positive policies it'll be a sweet victory indeed."

The Coalition is also facing a significant threat from the Nick Xenophon Team (NXT) in South Australia which is poised to win at least three Senate seats; enough to give the minor party significant power in the new government.

Polling suggests that NXT could also win seats in the House of Representatives with the Coalition-held seats of Mayo, Barker and Grey presenting their best chances.

The Greens, another minor party, is optimistic of stealing seats off both the Coalition and Labor in Victoria.

Greens leader Richard Di Natale spent election morning campaigning in the northern Melbourne seat of Batman where the Greens' candidate Alex Bhatal is a good chance to take the seat from Labor's David Feeney.

"People here who have voted Labor all their life are saying 'Thank goodness we've got you here, we haven't seen a politician in this part of Batman before'," Di Natale said on Saturday.

"We're very excited about our prospects here. I think there's a real chance we'll get over the line."

The Greens are also an outside chance to win the traditionally safe Labor seat of Wills and the Coalition-held Higgins in Melbourne's southeast. Endit