The NSW by-election in the Upper Hunter next weekend is likely to be decided by preferences with polling showing a wafer thin margin between the leading candidates.
A YouGov poll published in The Daily Telegraph on Monday has the Nationals struggling to hold the previously blue ribbon seat, meaning preference flows will be critical.
It's a must win seat for the Berejiklian government which will be left up to three seats in minority unless the Nationals hold the seat on Saturday.
The poll found the Nationals hold a narrow 51-49 two party preferred lead in the crucial by-election in the coal mining district.
The YouGov poll of 400 people conducted in the Upper Hunter last week found 25 per cent support for Nationals candidate Dave Layzell while Labor's Jeff Drayton is sitting on 23 per cent.
Shooters Fishers and Farmers candidate Sue Gilroy has 16 per cent support, while One Nation's Dale McNamara holds 11 per cent support.
The Greens Sue Abbott has six per cent support, the same as farmer Kirsty O'Connell - who is being supported by former Liberal prime minister Malcolm Turnbull.
A hefty 19 per cent of people remain uncommitted in the seat.
Last election the Nationals won 34 per cent of the primary vote.
On Monday Deputy Premier John Barilaro joined Mr Layzell to announce mining communities in NSW would receive $75 million more in royalties, with Resources for Regions Round Eight applications now open for projects to improve local amenities and infrastructure.
It followed Labor's announcement on Sunday that it will overhaul the program to redirect resource royalties back to mining communities, ensuring those regions receive at least $100 million per year from the scheme.
The by-election was sparked by Nationals MP Michael Johnsen's resignation in March after being accused of raping a sex worker in 2019.
Mr Johnsen denies the allegations and has not been charged.
Last week a fourth government MP was forced to move to the crossbench.
Families Minister Gareth Ward stepped aside on Thursday after it was revealed he is the subject of a police investigation into historic sexual violence allegations.
Former sports minister John Sidoti is also on the crossbench while the ICAC investigates corruption allegations.
Matthew Mason-Cox was also expelled from the Liberal Party earlier this month after defying Premier Gladys Berejiklian by nominating for president of the upper house.
Australian Associated Press