Senior National Party MP for Northcote Jonathan Coleman is defending his decision to leave Parliament within six months of the general election, forcing a by-election in his Auckland seat.
The former Health Minister has announced he's stepping down to take up a role as chief executive of the private hospital owner, Acurity Health Group.
His departure means there will be a by-election in his Auckland seat.
He is the third senior National Party MP to quit in recent months. His announcement follows the recent departures of Bill English and Steven Joyce.
"I was not looking to leave Parliament, but received an unsolicited approach from Acurity," Dr Coleman said.
"It's a very exciting opportunity that utilises my skills and draws on my background both outside and inside Parliament."
He made no apology for vacating his seat so early in the parliamentary term.
"Actually it's worse for a party the later a by-election is in the cycle, the closer it is to the next general election...because parties have their plan set."
And there were personal considerations, he said.
"Sometimes you get these moments in life, I've got to look at my future career track and this creates a chance to create a significant career outside politics."
He had no regrets from his time in Parliament, including as Health Minister.
"Health is a portfolio where you'll never please everybody all the time and you'll always be able to find specific cases where not all people have got every operation they might have wanted.
"But if you look at the statistics overall we consistently increased access to services across the board."
Dr Coleman starts his new position at the end of April and said he would confirm the date he'll resign from Parliament in the next few days.
National Party leader Simon Bridges has thanked Dr Coleman for his "many years of dedication and service to the National Party and New Zealand" and wished him and his family all the best.
"Jonathan has had a long and distinguished career in politics, including 13 years as MP for Northcote and nine as a Minister," he said.
Mr Bridges said he had been a "diligent and committed colleague" who handled a range of challenging portfolios".
Dr Coleman held a range of portfolios under governments led by both John Key and Bill English, including Health, Defence, Immigration and State Services.
He won the Northcote seat in 2005 and which he retained in the 2017 election with a majority of more than 6000 votes.