Deputy Premier Troy Grant stood down as leader of the NSW Nationals on Monday after the party suffered a devastating result in the Orange state by-election.

NSW education minister Adrian Piccoli has followed suit, announcing he will be stepping down as deputy leader of the state’s National party.

Mr Grant was facing a party room leadership spill Tuesday.

Orange has been in Nationals’ hands for almost 70 years, but the party is barely holding on after suffering a whopping 36 per cent swing against it at the weekend.

The party is expected to lose the seat to the Shooters, Fishers and Farmers party.

In a statement Monday, Mr Grant said the result was a clear message the Nationals “haven’t always got it right”.

Nationals candidate Scott Barrett holds 49.72 per cent of a two-candidate preferred vote, while Philip Donato from the Shooters Fishers and Farmers party is slightly ahead on 50.28 per cent.

Voter anger at the government’s proposed greyhound ban is said to have affected the swing. Photo: AAP

The tight race is expected to come down to Labor preferences (which were directed to the SFF), and if Mr Donato does win he will be the party’s first lower house representative.

The Nationals had held Orange by a 21.7 per cent margin and the incredible swing was described as an “electoral earthquake” by jovial Opposition Leader Luke Foley, buoyed by by-election wins in Wollongong and Canterbury at the weekend.

Nationals MP Andrew Fraser told the ABC he would put up a leadership still motion at the first party room meeting on Tuesday after the backlash.

Blue Monday for Grant

Throughout the weekend, Mr Grant had stood firm in his intention to continue the leadership, but a statement published on his social media accounts on Monday afternoon announced he would be stepping down.

“It has been an incredible privilege to serve in that role and lead a team whose sole focus is to serve the people of regional NSW,” he wrote.

Philip Donato would be the SFF’s first lower house member. Photo: ABC

“At all times I have been guided by my principles of honesty, integrity and hard work but I accept the result in Orange is a clear message that we haven’t always got it right, nor have we always taken the community with us.”

Disillusioned voters send clear message

The massive swing against the Nationals – up to 60 per cent in some polling booths – is believed to be a showing of voter anger over NSW Premier Mike Baird’s forced council mergers and the now-collapsed greyhound racing ban.

SFF upper house MP Robert Brown told Fairfax the swing was akin to Donald Trump’s shocking win over the establishment in America last week.

“Like the Trump election, this is not going to plan, especially for the Nationals,” he said.

The result was compared to last week’s landmark result in the US. Photo: Getty

“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.”

Mr Donato said he had sensed the anti-government sentiment during his campaign.

“The more people I met, the more doors I knocked on, the more communities I visited; it was clear that there was a clear cut resentment towards the National Party,” he told AAP.

Who are the Shooters, Fishers and Farmers?

Journalist John Tingle formed the SFF in 1992 in response to Prime Minister John Howard’s proposed national gun buyback laws, which he believed would limit Australians’ ability to defend themselves.

SFF’s current policies include the reversal of the gun reforms, which the party call “draconian”.

The party also wants to incentivise farming for young Australians, limit foreign ownership of Australian land and open all existing Australian marine parks to “sustainable recreational fishing”.