The National Party will run a "full marginal seat campaign" backing candidate, Cessnock mayor Alison Davey, after polling showed "we've got a shot" despite a 12.4 per cent margin to Labor, campaign director Ross Cadell said.

The tracking phone polls of more than 400 voters showed Ms Davey's name recognition among voters was "significantly higher" than Cessnock City Council colleague Neil Gorman, who withdrew from preselection for family reasons.

"We did the polling because before you go investing the campaign expenditure cap of $150,000 in a seat you want to know you're in the game," Mr Cadell said.

He refused to release figures but said another prominent Cessnock councillor, Greens candidate James Ryan, also polled well.

There was little difference between results for Labor names put to voters in the two separate polls in October and December. In October, voters were given the name of Labor councillor Bob Pynsent.

In December, they were given eventual Labor candidate for Cessnock, Clayton Barr.

Mr Cadell said the March election would be the first time Cessnock would be a marginal or contestable seat despite Liberal Bob Roberts' win in 1988.

"It's going to be a good, fun election because of the number of marginal seats, and the region will be better for it," Mr Cadell said.

Mr Hickey's retirement and the impact of the government's controversial electricity privatisation sale on local employer Hydro were in the Nationals' favour, he said.

Mr Hickey announced he would not recontest the seat after a Newcastle Herald article in which he admitted he lied about the birth of his baby daughter with a female parliamentary employee.