Foreign Minister Murray McCully: ""It is a real privilege to serve as Minister of Foreign Affairs. But it is an office that does not always sit easily with the role of a constituency MP." He has announced he will not contest East Coast Bays again at the election.

Foreign Affairs Minister Murray McCully will not stand for re-election in his East Coast Bays electorate at the next election.

But whether that means he will quit and force a by-election in the Auckland National stronghold, before the 2017 election, remains unclear.

The 29-year political veteran announced his stay in politics would only continue for as long as his tenure as Foreign Affairs Minister.

In the meantime, he would seek out options to remain a list MP, as Finance Minister and former Southland MP Bill English did at the 2014 election.

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"When my role as Foreign Minister comes to an end it is my intention to retire from Parliament.

"Quite when that will be, and whether I seek election as a List Member of Parliament in 2017, are decisions for the Prime Minister in the first instance," McCully said.

In a statement, Prime Minister John Key said McCully informed him of the decision "some weeks ago".

"He has served the people of East Coast Bays loyally for the better part of three decades and I thank him for his contribution to his community.

"Mr McCully is an outstanding and accomplished Foreign Minister and I look forward to him continuing to serve in this role for some time."

McCully has held the Auckland East Coast Bays seat since 1987, aside from two terms from 1996-2002 where he was the MP for Albany.

He said he advised his electorate AGM of his decision last night.

Significant health issues and major surgery, undergone by the Foreign Minister late last year, were not a factor in his decision, McCully said.

In November, McCully was understood to have required major surgery to remove a tumour. He was given the all clear by doctors after it was found to be benign, but took the rest of the year off on medical leave.

Speculation of his retirement reached a high ahead of the 2014 election, when it appeared at least some consideration was given by the Prime Minister to strike a deal in the National stronghold with former Conservative Party leader Colin Craig.

The deal would have been similar to that in Epsom, between National and ACT, where Key instructs supporters to vote for the Government support partner to boost seat numbers in Parliament.

Key eventually decided against such a deal, and Craig was later forced to stand down from the party amid sexual harassment allegations, which he strenuously denies.

In October last year, McCully steered a New Zealand diplomatic team to victory after a six-year campaign to secure a seat on the United Nations Security Council.

But most recently, his presence in the headlines has included his role in both the controversial Saudi sheep farm deal, and his ministry's bungling of a case in which a Malaysian Diplomat indecently assaulted a young Wellington woman and was briefly allowed to flee back to Malaysia.

McCully said it was a "real privilege" to serve as Minister of Foreign Affairs, but it did not always "sit easily" with the role of a constituency MP.

"At the end of this term I will have served as the local Member of Parliament for 30 years. This is the right time for me to announce my intentions and clear the way for an orderly succession process."