Long-term Ōhāriu MP Peter Dunne has said that after 33 years in Parliament, he did not want to risk losing on election night.
The United Future leader told RNZ he makes no pretense for the reason behind his departure from Parliament following the election.
"With a good strong campaign over the next few weeks, I could have won, but I wasn't absolutely certain of that.
"I thought after 33 years, why expose myself to that risk? There is a more graceful way to depart."
He said he had seen renewed support for the Labour Party as a vehicle for change following Jacinda Ardern's appointment as party leader.
Mr Dunne denied his resignation was a tactical move to help National's Ōhāriu candidate, Brett Hudson.
"It's a move by me because I have recognised what I think is the mood of the electorate and I respect that, that's their absolute right.
"I think having said that, [my resignation] will help the National Party cause ... it will make Brett Hudson's election all the more likely, but it is certainly not done for that purpose."
He believed Mr Hudson, who has been working in the electorate for the last three years, could win the Ōhāriu seat.
"If you look at the party vote in the Ōhāriu electorate, it has favoured the National Party in the last three elections by quite considerable margins.
"I think a clear two-tick campaign for National should now secure a significant number of those voters for their candidate."