Justice Minister Simon Power has announced his shock retirement from politics at the next election.
The fourth-ranked minister - often touted as a potential future National Party leader - said he would stand down from Parliament in November.
Power, a former lawyer, said he planned to pursue work in the private sector.
"It's time for new challenges and new opportunities.
"I've been extremely privileged to serve in the Cabinet under Prime Minister John Key, and as the Member for Rangitikei since 1999.
"It's been an exciting and rewarding time and I've achieved a lot, but now I feel it's time to move on to something else."
He said he had discussed his decision with Key and Deputy Prime Minister Bill English before announcing it.
Power is Minister of Justice, Commerce and State Owned Enterprises and minister responsible for the Law Commission.
He is also Associate Finance Minister, and Deputy Leader of the House.
As Justice Minister, he has overseen major reforms to the criminal justice sector and liquor laws.
He has also undertaken less high-profile reforms of the commerce sector, including changes to financial market rules.
He said Key had allowed him to remain in his portfolios till the election.
Key said he regretted Power's decision, but wished him well.
"I am saddened that he will be retiring from politics at the election and he will be a great loss to National.
"Mr Power has worked extremely hard and has been completely on top of his many important portfolio responsibilities.
"I was informed of his decision on Sunday night. It has come as a complete surprise, as I'm sure it will to most people in the National Party and the Government.
"However, I accept his decision. Mr Power is hugely talented and has been dedicated to his political career. He is a loss to New Zealand politics, but I'm sure that he will continue to make an outstanding contribution to New Zealand in whatever he does next."
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