The NSW Nationals are in serious danger of losing the regional seat of Orange with early by-election results suggesting a massive swing of more than 30 per cent against the party.

With almost half the votes counted on Saturday night, Nationals candidate Scott Barrett was on 29.5 per cent, while the primary swing against the party stood at a devastating 36.1 per cent.

The Shooters, Fishers and Farmers’ (SFF) candidate Philip Donato is close second on 25 per cent and the minor party looks likely to secure the central-western seat on Labor preferences.

Philip Donato knows that if the @NSWNationals & @Scotty_Barrett are re-elected tomorrow, nothing will change in Orange #nswpol #OrangeVotes pic.twitter.com/WnTzjkUuCR

— SFF Australia (@sffAustralia) November 11, 2016

Shooters, Fishers and Farmers upper house MLC Robert Brown said the result had exceeded the party’s expectations. “Like the Trump election, this is not going to plan, especially for the Nationals,” he told the Sydney Morning Herald.

“I don’t know if we will get there, but this will teach the Nationals a lesson. They have to grow a spine and not kow-tow to the Baird Government.”

The results appear to have cemented the coalition’s fears of a backlash over the greyhound racing ban and come despite Premier Mike Baird’s spectacular backflip on the controversial policy last month.

Some of the worst results for the Nationals also appeared to be in areas impacted by the state government’s proposed council amalgamations, with a polling booth in Molong recording an unprecedented 60 per cent swing against the party.

Unless there is a very strong National vote with Postals and Pre-polls, they will lose Oranage to the Shooters, Fishers and Farmers Party

— Antony Green – elections (@AntonyGreenElec) November 12, 2016

The Shooters, Fishers and Farmers declined to claim victory on Saturday but Mr Donato said he’d be very surprised if the party didn’t win.

“Irrespective of tonight’s result, it’s clear Orange deserves better and they want better,” he said.

The SFF have two members in the upper house but have never held a lower house seat in NSW.

Orange has not changed hands since the end of World War II and was held by the Nationals by a massive 21.7 per cent margin.

The seat became vacant earlier this year when former MP Andrew Gee resigned to run for federal parliament.

A loss could spell the end of Deputy Premier Troy Grant’s tenure as the Nationals state leader.

While campaigning in Orange earlier on Saturday, Mr Grant vowed to stay on in the top job irrespective of the results.

Labor meanwhile claimed victory in the two other by-elections on Saturday.

In Sydney, upper house Labor MP Sophie Cotsis looked certain to retain the seat of Canterbury with an impressive 15 per cent primary swing.

The seat was left empty following Linda Burney’s switch to federal politics in May.

Labors Paul Scully thanking supporters for a great win in the Wollongong by-election. Meanwhile in Orange sh_t gets interesting #nswpol pic.twitter.com/h3WValE3Sc

— Stephen Jones MP (@StephenJonesMP) November 12, 2016

Further south in the Illawarra, Labor candidate Paul Scully also appears to have won the seat of Wollongong – left vacant after long-time MP Noreen Hay controversially quit earlier this year – on a 9.3 per cent primary swing in the ALP’s favour.

Labor opposition leader Luke Foley said the three results were a clear protest vote against the Baird government.

“I challenge Mr Baird to come into parliament this week with a plan to scrap all forced council mergers; to allow a paliamentary vote on Labor’s legislation to revoke the greyhound racing ban this year; and abandon its privatisation of hospitals,” he said.