Nats want another chance in regional NSW

NSW Nationals leader John Barilaro has urged country constituents to hold fire and not lodge a protest vote for the Shooters party in this weekend's state by-elections and instead let his party prove its worth ahead of the 2019 poll.

The Nationals face tough fights to retain Murray and Cootamundra on Saturday while Labor is expected to hold the Sydney seat of Blacktown with relative ease.

The Shooters, Fishers and Farmers Party is hoping to take advantage of lingering voter anger over the aborted greyhound racing ban and forced council amalgamations to take the seats of departing National MPs Adrian Piccoli and Katrina Hodgkinson.

Barilaro, who claimed the leadership after his predecessor Troy Grant resigned when the Nationals lost Orange to the Shooters in a late 2016 by-election, says he has no intention of falling on his sword if the party suffers a similar defeat on Saturday.

"My job won't be completed until 2019," Barilaro told reporters this week.

"If they keep us in this time and we don't deliver by 2019, they have an opportunity to throw us out and, you know what, I'd say to them 'throw us out if we haven't delivered'."

The Nationals, anticipating a strong protest vote in the two rural seats, this week enlisted the help of former prime minister John Howard and his deputy then-federal Nationals leader Tim Fischer.

The pair, with help from Barilaro's office, penned a letter warning country voters that the Shooters' first priority was to "fundamentally weaken our existing firearms laws".

It's an irony of the campaign that the Shooters, once considered a single-issue party, have run on a broader range of issues while the Nationals have zeroed in on gun laws.

Fischer this week suggested the Shooters candidates had adopted the "tactics and terminology" of the National Rifle Association in the US.

The Shooters say such attacks stink of desperation.

"We've shown we're beyond a one-issue party, we've represented the interest of the greyhound industry, we've represented the interests of local councils," Shooters, Fishers and Farmers Party MP Philip Donato told reporters.

ABC election analyst Antony Green says the Nationals are most worried about losing Murray.

Shooters candidate Helen Dalton, who came second behind Piccoli in the 2015 state election as an independent, will prove a tough match for the Nationals candidate Austin Evans, Green told AAP.

"She has a much broader range of issues to run on as well - irrigation is a much bigger issue in Murray than it is in Cootamundra."

In Cootamundra, the Shooters' Matthew Stadtmiller will battle Nationals hopeful Steph Cooke, a local florist who's hoping to replace the outgoing Hodgkinson who's leaving after 18 years in parliament.

While ongoing federal issues may play a small part in the by-elections, they will overwhelmingly be decided on state issues.

A loss in either seat won't cause Premier Gladys Berejiklian any problems in parliament - where the coalition has a comfortable majority - but Green argues it would be a clear sign that tensions in Australia's conservative ranks are far from resolved.

In the third seat to be decided on Saturday, former Labor leader John Robertson should be replaced by Blacktown Mayor Stephen Bali in the western Sydney seat.