NSW Premier Gladys Berejiklian has shouldered the blame for the historic swing against her government in the Wagga Wagga by-election.

Counting from Saturday’s by-election is continuing but a projected swing of about 29 per cent against the government is tipped to make independent Joe McGirr the seat’s new occupant.

It could take days for preferences to clearly name the winner but candidate Julia Ham will not hold the seat for the Liberal Party, Ms Berejiklian acknowledged on Sunday morning.

The people of Wagga Wagga, she said, had sent the government a “strong message” that they are sick of political infighting, instability and navel-gazing.

“They’re angry and disappointed with politicians talking amongst themselves and not focusing on the community, and they also want me and my government to make sure we don’t take them and their community for granted,” she told reporters in Sydney on Sunday.

“I’ve heard that message loudly and clearly.”

As seemingly inevitable defeat of the Ms Ham will mark the first time in more than 60 years a Liberal has not held it.

Addressing supporters in his Wagga backyard on Saturday night, Dr McGirr said he was feeling “quietly optimistic” but didn’t expect a result until Sunday.

The doctor, academic and climate change crusader ruled out joining the Coalition once in government.

ABC analyst Antony Green agrees that Dr McGirr has good reason to be optimistic.

“It appears that of the three [chief] candidates in this contest, the Liberals are currently the least likely to win,” he said .

No matter the outcome, Labor candidate Dan Hayes declared the community had “made Wagga marginal again” after arriving at the election night reception to rapturous applause.

“We’ve been neglected for too long, for too long, and we’re sending them a message: we won’t be neglected anymore.”

A troubled campaign bookended by a local corruption scandal and a messy federal leadership coup has eroded the government’s once-safe 12.9 per cent margin, senior government sources say.

The Liberal Party has held the safe Riverina seat since winning it in a by-election in 1957. It was vacated by disgraced MP Daryl Maguire, whose resignation forced the byelection.

Ms Ham told the subdued crowd at her post-poll gathering that she would consider running in March if the anticipated loss eventuated.

“It may be over [tonight], but it’s something that I would certainly stand for again,” Ms Ham said.

Both Mr Hayes and Dr McGirr agreed earlier in the day there was an appetite for change in the community.

Mr Hayes said local and national scandals have stoked community anger – a view echoed by Dr McGirr, who said he could feel the shift at polling booths as traditional Liberal voters arrived to cast their ballots.

“There is definitely an appetite for change, just uncertain where that’s going to go,” he said outside a polling booth in Wagga.

Ms Berejiklian acknowledged Malcolm Turnbull’s knifing deterred some voters in Wagga, compounding the local reaction to the scandal-clouded resignation of of former Liberal member Daryl Maguire.

Voters “expect the highest level of integrity from all members of parliament, and there’s no doubt the actions of the former member led to a lot of anger and disappointment,” she said.

“But, of course, so did the later instability at other levels of government.

“The timing of the by-election, which coincided with other major events, other major political events, could not have been foreseen.

“It was the perfect storm.”

Ms Berejiklian said she had spoken to Prime Minister Scott Morrison early on Sunday and both leaders were “clear” they had to govern and take the focus off political sniping and turmoil.

-with AAP