"But I haven't lost that passion yet."
He will be defending his seat against at least three other contenders - including an as-yet -unannounced National Party candidate.
Nominations for the National candidacy closed on Friday. Yesterday Napier electorate chairman Ian Mayne remained tight-lipped about the number of nominations received.
He said he had been told nominations were confidential, and "would be informed in due course".
National's 2014 candidate Wayne Walford has confirmed he will not seek the candidacy again. He was selected over Hastings District Councillor Adrienne Pierce, and Taradale author and businesswoman Deborah Burnside.
Party rules state once the pre-selection process has begun, nominees cannot discuss whether they have put their names forward.
Now 60 delegates will be chosen to consider the prospective candidates, nominated by both Napier and Tukituki electorate party members. The party hopes to announce the selected candidate by March 25.
Mr Nash said he did not care who National selected as a candidate, because he would always "concentrate on the issues that are important to Napier".
Past campaigns had been clean, and "done in a really robust and positive way", he said. "I don't see that changing no matter who they select".
Also contesting the seat will be Green Party candidate Damon Rusden.
The 22-year-old former Napier resident said he was feeling "absolutely prepared" for the contest, and had been engaging with as many parties and people as possible.
"I'm happy to take on whoever National selects," he said. "I'll be here talking to people about the issues, engaging with the community and with youth."
Also vying for the seat will be seasoned Democrats for Social Credit candidate Barry Pulford. This will be his sixth time tackling the polls - he first stood under the party's banner in 1990.
New Zealand First president Brent Catchpole said the party would be standing a candidate in the electorate but had not made a selection yet. He hoped NZ First would announce its candidate before the end of March.
Act's Lower North Island board member Jim Rose said the party had not selected any candidate to stand in the electorate at this stage, but did not rule it out.
A Maori Party spokesperson said the party did not intend to stand a candidate.
The Conservative Party did not respond to requests for comment. When the party's 2014 candidate, Garth McVicar, was asked if he would be vying for the candidacy again, he said "definitely not".
The Labour Party has also selected its candidate for Wairarapa. It is Kieran McAnulty, who stood in the 2014 election. He lost to incumbent National MP Alastair Scott.
The election date has been set as September 23.
