Grassroots members of The Nationals will determine their next candidate for the federal seat of Cowper.
Party officials have confirmed that nominations for preselection for Cowper are now open.
With current member Luke Hartsuyker calling time on his 17 year career representing the electorate, party members will have the opportunity to have a say on their candidate, a spokesperson said.
"The Nationals' preselection process is one of the finest examples of democracy in action, with grassroots members getting a say on who will represent them in Parliament,” the spokesperson said.
Prospective candidates for the preselection process have until 5pm on Friday September 21 to nominate as part of the process.
A preselection meeting will be held after nominations close, at a time and location yet to be determined.
"The Nationals thank outgoing Member for Cowper Luke Hartsuyker for his many years of service to the party and his electorate."
With The Nationals' still several weeks away from announcing their candidate for the federal seat, The Greens have confirmed Dr Sally Townley as their candidate while the ALP has nominated Andrew Woodward as their candidate.
Independent candidate at the 2016 election and former federal MP for Lyne, Rob Oakeshott is yet to confirm if he will contest the next election.
The seat of Cowper covers some 7296 square kilometres and is named after Sir Charles Cowper, who served as the NSW Premier from August 25 until October 2, 1856.
The electorate includes the cities of Port Macquarie and Coffs Harbour with other major centres including Kempsey, Nambucca Heads, Macskville and South West Rocks.
Mr Hartsuyker has served the electorate for 17 years, retaining the seat for the conservatives in 2001 from the then retiring member Gary Nehl.
Mr Hartsuyker topped the poll at the 2016 election and holds the seat with a 4.56 per cent margin on two candidate preferred over Independent candidate Mr Oakeshott.
The seat has been considered conservative since Francis Clarke claimed the seat in the first federal election in 1901 for the Protectionist Party.
Earle Page held the seat for close to 42 years from 1919. He was the caretaker prime minister when he contested the 1958 federal election.
The ALP did hold the seat in 1961 for two years when Frank McGuren snatched the seat from Mr Page, who was gravely ill. Mr Page subsequently passed away, 11 days after the election unaware that he had lost the seat.
An election date is yet to be set by Prime Minister Scott Morrison.