The former Minister for Defence, who has held the role since 1996, will run number seven on the ballot paper, and take on The Nationals' Josh Angus, One Nation's Stuart Bonds, United Australia Party's Paul Davies, Janet Murray of the Greens, Animal Justice Party's James Murphy, Christian Democrat Party candidate Richard Stretton, who also ran at the state election, and Socialist Equality Party's Max Boddy.

Mr Angus is expected to be the biggest competitor given his recent for the state election in Cessnock where he secured a 3 per cent swing in the Nationals' favour.

The Hunter Valley cafe owner is a strong advocate for extra mental health services and is calling for more funding for headspace centres in regional areas, and is also a supporter of the coal industry.

"There are a lot of people in the Hunter who are employed either directly or indirectly by the coal industry, and we need to protect those jobs," he said.

Ms Murray, a chemical engineer, is focused on trying to ease the region through a transition away from coal mining, and said the way Newcasle shifted from steelworks, an industry she worked in for nearly 20 years, shows it's possible.

"The community will embrace any plan that also ensures today's mining and power workers have access to training that leads to meaningful employment in 21st-century jobs."

Mr Bonds says he is stepping up to be a sensible and unwavering voice for countless Australians who feel their issues are being ignored by major political parties.

"I'm the voice of millions of unheard people out there that are just ignored because they don't have the voice or the means or the will to get out there... and there's nobody out there speaking up for them," he said.

"I've got to do it."

Boating and fishing enthusiast Mr Davies has worked across a variety of roles throughout his life, and has said he has joined the party to help build a better life for his children and grandchildren.

The One Nation candidate will run first on the ballot paper order, followed by Mr Angus, Mr Murphy, Mr Davies, Ms Murray, Mr Stretton, the incumbent Mr Fitzgibbon and finally Mr Boddy in eighth place.

Early voting starts on Monday April 29 with electors in Singleton able to cast their vote at Units 2 and 3 77 John Street. The building is opposite Singleton Square - and the best carparking would be available in that centre.