New South Wales Deputy Premier John Barilaro is claiming “a great victory for the party” in the critical Upper Hunter election.

Nationals candidate Dave Layzell is on track to claim a resounding victory and a swing to the party, despite scandals within the Coalition.

The result pushes state Opposition Leader Jodi McKay’s leadership into more doubt. The party’s primary vote in the seat is down seven points from last election.

Last night Ms McKay told supporters the result isn’t an endorsement of the Government.

The New South Wales government is well on track to defy history by retaining the marginal seat of Upper Hunter in the byelection.

Almost 50 percent of the vote has been counted, with the Nationals confident its primary vote and preferences are strong enough to get the party over the line.

Clinton Maynard spoke to Nine News State Political Reporter Liz Daniels live from Singleton.

She’s explained how the results unfolded and what it means for the leadership of both Gladys Berejiklian and Jodi McKay.

Click play below to listen to the interview.