A former coal miner, Mr McNamara now operates coal mining services businesses as well as pubs and commercial property in Singleton and Branxton.

In a statement released by One Nation this morning NSW One Nation leader Mark Latham MLC described Mr McNamara as fighting for coal mining jobs first and foremost.

"Dale's first priority is economic development, protecting coal jobs and assisting every industry in the Hunter region that can help drive down unemployment and give young people local future employment opportunities," Mr Latham said.

Speaking to Singleton Argus on Tuesday, Mr Fitzgibbon said parties like One Nation could pose a threat to Labor retaining Hunter if voters did not feel they would find economic security under a Labor government.

"What happened during the last election campaign is that people lodged a very strong protest vote, with One Nation in particular, because they felt that Labor had lost focus on their needs and aspirations," Mr Fitzgibbon said.

"This time around, I'm confident they won't feel that that is the case and they will come back to the Labor party."

Labor has yet to announce how it will select its candidate, but speaking to ABC Radio on Monday Mr Fitzgibbon named a number of local candidates who could potentially succeed him, including former coal miner Jeff Drayton, local nurse Emily Suvaal, barrister Stephen Ryan and Olympian Daniel Repacholi.

Mr Drayton and Mr McNamara were both unsuccessful candidates for the seat of Upper Hunter during the by-election in May.

Mr McNamara placed third behind Labor candidate Mr Drayton and the Nationals victor Dave Layzell.

Labor has held the seat of Hunter since 1910.