Decision day: Upper Hunter voters head to the polls for crucial by-election

IT'S decision day in the Upper Hunter electorate as voters head to the polls and candidates and political leaders make their final pitches in a bid to secure voters.

Election day polling began at 8am this morning and continues until 6pm. See a list of polling places here.

There are 13 candidates running for the state seat of Upper Hunter, which has been held by the Nationals for 90 years, and they cling on to by a margin of just 2.6 per cent.

The seat is up for grabs due to the resignation of former Upper Hunter Nationals MP Michael Johnsen over allegations of sexual assault and a sexting scandal - an allegation he denies.

There is a lot on the line for the Coalition, who risks slipping further into minority government if they lose the seat, after Kiama MP Gareth Ward moved to the crossbench after he was accused of sexual violence, and Drummoyne MP John Sidoti stood down from the Liberal Party temporarily while he faces a corruption inquiry.

Key issues that have dominated the campaign include the future of the mining industry in the region, roads and health - with funding promises for the Singleton Bypass and Muswellbrook Hospital dominating discussion - and education following the NSW government's recent sale of the Scone TAFE campus.

More than 40 per cent of the electorate had already cast their vote before Saturday, with 34.40 per cent voting at pre poll, 5.48 per cent using postal voting and 3.47 per cent making their decision via iVote.

Meet the candidates below (listed in ballot order).

Click on the links to meet the candidates in ballot order:

Archie Lea (Independent)

Eva Pears (Liberal Democratic Party)

Michael Dello-Jacovo (Animal Justice Party)