A by-election will be held in the safest seat in NSW after former minister Adam Marshall's announcement that he will retire from politics.
Mr Marshall retained the Northern Tablelands electorate, in the state's north, for the NSW Nationals at the 2023 election with the largest margin of any seat.
He plans to formally hand in his resignation on May 13.
"This is not a decision I have made lightly, but it's one I'm now very comfortable with," Mr Marshall said in a statement on Thursday.
"Put simply, I feel it's time for me to move on and take up new challenges."
Mr Marshall said he intended to pursue work in the corporate sector as well as other opportunities in his personal life, adding that it would be the end of his time in representative politics.
He held cabinet positions in the former coalition government as minister for agriculture, western NSW, and tourism and major events.
Mr Marshall won the Northern Tablelands seat for the Nationals at a by-election in 2013 following the departure of independent Richard Torbay.
NSW Nationals leader Dugald Saunders said Mr Marshall had been a great local member and community advocate over the past decade.
"Whether bushfires, drought, COVID or the escalating regional crime crisis, Adam and the NSW Nationals have always had the region's best interests at heart," he said.
Mr Marshall appeared alongside Premier Chris Minns in Moree on Wednesday to announce initiatives aimed at reducing youth crime, praising the Labor leader's response to the issue.
"We do have some very serious issues in our community, but we won't fix them by sniping from the sidelines, by being overly political and partisan," he said.
Mr Marshall retained the seat with 71.6 per cent of first-preference votes in 2023, giving him a margin of more than 33 per cent after preferences.
The similarly Nationals-held seat of Cootamundra in the Riverina region and the Labor stronghold of Wallsend in suburban Newcastle are the only two other state seats held on a margin of over 30 per cent.
Nine other candidates battled Mr Marshall for the seat in 2023, tying with the electorate of Murray for the most people in the running.
But only one challenger, Labor candidate Yvonne Langenberg, attracted more than 10 per cent of first-preference votes.
