New South Wales Treasurer Matt Kean says the Coalition winning the state election will be as difficult as climbing Mount Everest.
Millions of votes are being counted across New South Wales after polls closed at 6pm.
Mr Kean tonight told the ABC the priority for the Coalition was holding onto seats in Sydney's west.
He also conceded it was a tough battle ahead.
"The deck is stacked against us here. It is going to be Mount Everest.
"It would be an historic victory because it hasn't been done before, four terms, so fighting the tide of history is like fighting gravity."
Live coverage: follow the latest develpments on the ABC's NSW election blog
ABC's election analyst Antony Green tonight declared "the swing is on" for Labor.
Mr Green said some "meaningful" figures were starting to drip into the system.
"We can't call it at this stage, but the swing is on," indicating red Labor seats.
Meanwhile, outgoing Transport Minister David Elliott has said the Coalition was already admitting defeat in the Liberal-held seats of the South Coast and Parramatta.
The electorate in Western Sydney was considered one of the easier gains for Labor, after popular Liberal MP Geoff Lee announced he was retiring at this election.
Mr Elliott said the South Coast result was "a shock".
'It just appears that the vote couldn't hold up with a new candidate and we're likely to lose that with a significant swing against us," he said.
ABC predictions are also pointing to an ALP win in the south coast seat of Heathcote.
Labor's Maryanne Stuart has taken the marginal seat, due in large part to the southern seat’s redistribution.
As the day unfolded, both Premier Dominic Perrottet and Opposition Leader Chris Minns, looked buoyant and hopeful as they cast their votes in their respective electorates earlier today.
Flanked by his wife Helen, Mr Perrottet was out early in the blue ribbon seat of Epping in Sydney's north, casting his vote at Beecroft Public School.
He has held the seat comfortably since 2019, and was confident he would retain it.
"We were the worst-performing economy over a decade ago. The state had stalled. We've turned that around," he said.
Showing off a tired baby Celeste, the family unit then made their way to East Hills.
The crucial seat is currently sitting on a knife's edge, held by Liberal MP Wendy Lindsay with a margin of 0.1 per cent.
Mr Minns also made an appearance in East Hills, joining Labor candidate Kylie Wilkinson.
The Opposition Leader then made a lunch-time appearance at Kogarah, where he cast his vote alongside wife Anna and his three boys.
In the electorate of Oatley, Mr Minns was asked about the latest Newspoll results today, that put him ahead of the premier on a two-party-preferred basis.
"It's a cliche, but when a poll comes out on polling day ... it's more important to say to the people of New South Wales, go and cast your vote," he said.
"There's nothing more important than an actual ballot in a ballot box.
"We've got a positive plan for change."
This year a record number of postal votes were cast, with 1,566,493 early votes already cast.
Not only does Labor need to flip nine seats to end the Coalition's 12-year reign, but Mr Minns needs to retain the southern seat he came close to losing at the 2019 election.
He holds it by a margin of 0.1 per cent.
During the election campaign he said Labor couldn't win without Kogarah, and he would "rather not be in parliament" if he couldn't represent the area.
Recent polls have Labor out in front, with the strong likelihood of a hung parliament that could see independents and minor parties playing a bigger role than usual.
According to Mr Green, all eyes tonight will be on the key battleground of Sydney.
"If you look at where the election will be decided, it will be mostly in Sydney, and the seats on five, six or seven per cent that Labor needs to win," he said.
Among those seats is Oatley in Sydney's south and the safe Liberal seat of Camden in south-west Sydney which the party holds by 7.3 per cent.
But to get there, Labor needs to first win Riverstone, Winston Hills, Parramatta and Penrith.
For the Liberals, the string of northern suburbs seats where independents are running will be key.
They will be monitoring closely teal challengers: Helen Conway in North Shore, Jacqui Scruby in Pittwater, Joeline Hackman in Manly, Victoria Davidson in Lane Cove and Judy Hannan in Wollondilly.
in the Liberal-heartland seat of Willoughby, independent Larissa Penn could pose a danger.
By Friday afternoon, more than one million people out of the state's five million voters, had pre-polled, with the NSW Electoral Commission receiving just over 92,000 postal votes.