Late on Sunday with 42,983 of the votes counted, Nationals candidate David Layzell had won 31.2 per cent of the primary vote ahead of Labor's Jeff Drayton (21.7%), who conceded victory earlier in the day. Labor's primary was down 6.8 per cent from 2019, which Mr Drayton said showed voters no longer saw the party "as the answer".

With a field of 13 candidates, the major parties were always likely to drop primary votes. One Nation's Dale McNamara (12.5%) polled third best ahead of the Shooters' Sue Gilroy (12.0%).

Malcolm Turnbull-backed independent Kirsty O'Connell performed well (8.6%) and was followed by Tracy Norman (4.0%) and the Greens' Sue Abbott (3.2%).

The independent and minor party candidates felt their presence ensured the electorate won greater attention from the Coalition.

"At the end of the day the Upper Hunter won," Ms Gilroy said. "They knew they had to come with the chequebook open if they wanted to retain the seat," Kirsty O'Connell added.

Deputy Premier John Barilaro said the result was consistent with the party's polling, which showed the party would win between 32 to 34 per cent of the primary vote.

"I was confident but it's a tight margin," he said.

"We won the Singleton pre-poll ... I would have thought Labor or One Nation would have picked that up. It just shows never underestimate the community."

The result has heaped huge pressure on Opposition leader Jodi McKay and despite some Labor MPs downplaying the impact, sources suggest her time as leader is sure to come an end.

Ms McKay said Labor's message "didn't resonate" and despite the progress she thought the party had made, it still had "fundamental issues".

"When I became leader I made a commitment to change our party, and in some ways this by-election came too early, because the change that we're implementing is still ongoing," she said.

"People didn't hear our message and that is fundamental to the changes that we, as a party, need to make."

RELATED READING:

But Mr Barilaro said he believed Labor's policy platform, not Ms McKay, was its fundamental problem.

"Everyone is talking about Jodi and her leadership but Jodi is only the front face of the party," he said.

"The problem ... is the policy settings, the negative campaigning that they have done for 10 years, anti-everything that we have stood for.

"You can't just turn up on the eve of an election and pretend you are backing agriculture and mining when your actions on the floor of the parliament over the past decade have been quite the opposite."

Mr Drayton, a union official who presented as a coal miner, polled strongly where he was best known around Muswellbrook but failed to win votes around Singleton.

He said Labor needed to do "some real soul searching" to win back voters.

Federal MP Joel Fitzgibbon said "traditional working voters" Labor had lost to other parties in recent years would not be regained "overnight" and the soul searching had to start with them.

"The Labor party always has to be the party of job security and financial security for working families," he said. "Globally we are going through a period of rapid change and that causes some insecurity in our society.

"We need to be providing reassurance that we'll concentrate on making sure they are not adversely affected by change, and in fact create opportunity out of change."

Mr Fitzgibbon admitted he was "concerned" about retaining his own seat given the weekend's results and Labor should be "worried" with Scott Morrison "clearly" targeting multiple Labor-held seats in the region.

The Coalition has its sights set on Mr Fitzgibbon's seat of Hunter, Paterson held by Meryl Swanson and Pat Conroy's seat of Shortland.

Former Liberal staffer Brooke Vitnell and Nell McGill are firming to contest the later seats, but a Coalition candidate for Hunter is less certain.

"These seats are up for grabs, the whole lot, all that region," Mr Barilaro said.

"ScoMo with his ability, the right candidates, the right policy settings, I reckon they can strip some seats off the Labor party."

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: