Government Minister Peseta Sam Lotu-Iiga has announced he will not be contesting the 2017 election, and will be "exploring new opportunities".
He holds Local Government, Ethnic Communities and Pacific Peoples portfolios, is the Associate Health Minister and also MP for the Auckland electorate of Maungakiekie.
"In order to ensure a smooth transition, it is my intention to step down as a Minister when Prime Minister Bill English's new Cabinet is sworn in.
"However, I intend to remain as the MP for Maungakiekie until the next election to avoid the cost of a by-election", Mr Lotu-Iiga says.
Mr Lotu-Iiga says the decision hasn't been made out of the blue, and he has considered making a change for some time.
He says he had his mind made up even before John Key's shock resignation last week.
"I had always intended to inform the Prime Minister, my caucus colleagues and my electorate team of my decision this week, even before John Key announced his decision to resign last Monday".
He was elected to Parliament in 2008 and has previously held the portfolio of Corrections Minister.
It was during the time of the Serco 'fight club' scandal, and reports of prevalent drug use was at Mt Eden Prison.
He came under significant pressure during that time, and was later relieved from the role by Judith Collins.
Mr Lotu-Iga says the Serco debacle was "challenging certainly".
"But you know, at the same time we came to some conclusions on Serco in terms of Mt Eden that I think was good for the system and good for New Zealand.
"I handled it to the best of my abilities at the time, and I live with that."
He says he'll campaign hard for whoever stands in his place in Maungauiekie, and he believes National has a good chance in the electorate.
"I'm confident that we can win the seat, and you know it's a changing electorate, it's a diverse electorate."
National won Maungakiekie by just 2348 votes in 2014 - a narrow victory against Labour's Carol Beaumont.