Australia election: PM Malcolm Turnbull 'confident' of poll win
Australian PM Malcolm Turnbull says he is confident he can form a government after Saturday's election, but results are still too close to call.
The leader of the Liberal-National coalition needs to win 76 out of 150 lower house seats to form a ruling majority.
With about half the votes counted, results suggest a very close contest.
Opposition leader Bill Shorten said the close result was a vindication of his Labor Party's policies.
Labor has improved strongly on its 2013 election result of 55 lower house seats.
"There is one thing for sure - the Labor Party is back," he said.
All 150 seats in Australia's lower house, the House of Representatives, are up for grabs at the election, as are 76 seats in Australia's upper house, the Senate.
It is the first time in decades that all the seats in both houses have been up for election.
The double-dissolution election, as it is known, was called by Mr Turnbull in an attempt to break a deadlock over industrial relations legislation.
It was thought the result of the UK's referendum on the EU would benefit Mr Turnbull, who assured voters that he could deliver "economic certainty".
The former lawyer and investment banker vowed to deliver tax cuts for workers and small businesses.
Hardly a ringing endorsement: Jon Donnison, BBC, Sydney
Addressing supporters, Malcolm Turnbull tried to make tonight sound like a victory. But at best his Conservative coalition lost ground.
He said he was confident he would be able to form a majority government but he acknowledged the result was so close it could be days before we know the outcome.
Meanwhile, Labor Party Leader Bill Shorten was sounding upbeat telling his supporters Labor was back, even though he will most likely end up defeated.
Australia has had five prime ministers in the past six years. Mr Turnbull may have narrowly avoided adding to that tally but if he does turn out to be victorious this was hardly a ringing endorsement.
Buoyant mood at Labor HQ: Phil Mercer, BBC, Melbourne
They came wearing red T-shirts emblazoned with "We'll put people first" and "Proud to be Labor". Their hopes of an outright victory have been dashed, but they are buoyant.
The faithful arrived at the Moonee Valley Racing Club in Bill Shorten's constituency of Maribyrnong, hoping to witness election history by unseating a first-term government for the first time in more than 80 years.
For a while it was neck-and-neck. Labor loyalists, many enjoying beer, wine and party pies, turned up the volume.
But then there was a gradual realisation that an overall win was beyond them as Labor's momentum stalled.
Could there possibly be a fresh election if neither Labor nor the Liberal-National coalition can attract enough votes to form a government?
This will be part of the rich political theatre of the coming days and weeks.
Voting is compulsory in Australia and uses the alternative vote system where voters rank candidates in order of preference.
But so far results suggest that Australians voted in large numbers for independents and minor parties.
Senator Nick Xenophon's newly formed political party, the Nick Xenophon Team, took the lower house South Australian seat of Mayo, formerly a safe Liberal seat.
Mr Xenophon is expected to be returned to the Senate and his party may gain additional upper house seats, particularly in South Australia.
Pauline Hanson's One Nation party has polled strongly in Queensland and although it has not won a lower house seat, its preferences have tended to flow to the opposition Labor Party.
Ms Hanson, who gained notoriety for her anti-immigration views in the 1990s, told the Nine Network that, based on early results, she was likely to secure two spots in the Senate.
The government and the Labor opposition sparred during the campaign over the economy, healthcare, immigration and same-sex marriage.
Mr Shorten's claims that the government intended to dismantle Australia's public health system, Medicare, was widely credited with creating a late swing to Labor.