Mr Barr won back the seat comfortably, but it is looking like it will be by slightly less than his 22 per cent margin victory in 2015.

While Mr Barr said while he was disappointed his margin had decreased, he was "really happy, thankful and grateful" to be re-elected again.

"During the campaign there was plenty of commentary online to suggest I hadn't been working hard enough," he said.

"It's good to see that it's a silent majority that are happy with what I'm doing."

Mr Barr said he believed the most important issue in Cessnock was education, and that he would continue to lobby for more resources in schools.

He said Cessnock was the worst electorate in the state for education outcomes, and had been for more than a decade.

"Cessnock has been languishing in that regard,"  he said. "The government says 'Gonski will take care of that', but that's not the case.

"The 10 communities with the lowest education have remained there for the last few censuses. We need to target those 10 key communities and invest money into them."

Mr Barr said he would also continue to push for a new entry to the jail through the old Allandale Hospital.

"It's likely there will be a new Minister for Corrections," he said. "My job is to convince them to see the side of the community and just get the job done."

Mr Barr's Labor colleague, Cessnock deputy mayor Melanie Dagg came close to winning the Upper Hunter seat that has never been held by her party.

She secured 29 per cent of the primary vote to Nationals incumbent Michael Johnsen's 34 per cent.

Ms Dagg filled the vacancy created by the shock resignation of Muswellbrook Mayor Martin Rush who resigned his candidacy following the release of an anonymous letter in January.

The deputy mayor of Cessnock copped flak because she lived 200 metres outside the electorate's boundary.

"I knew when I agreed to run that it would be an uphill climb," she said.

"But I am heartened by the support we got across the electorate, including from people who told me they had voted National all their life, but in this election for the first time they voted Country Labor.

"Our commitment to deliver for the people of the Upper Hunter continues, and I will be working hard every day to hold this government to account."