WELLINGTON (AFP) - New Zealand Prime Minister John Key has made a habit of doing the unexpected during his political career, and he stayed true to form on Monday (Dec 5) when he abruptly resigned.
A millionaire ex-banker who exudes an everyman appeal with voters even after eight years in power, the 55-year-old was expected to win a record-equalling fourth term next year.
Instead, he announced he was stepping down and throwing open the leadership of his centre-right National Party.
"All I can say is that I gave it everything I had, I have left nothing in the tank," he told reporters.
Political commentator Matthew Hooton said it was typical that Mr Key wanted to leave on his own terms, rather than cling on to power as long as possible.
"The one thing about him, while he's an incredibly skilled politician, clearly there has always been an element of the anti-politician within him," Mr Hooton told Radio New Zealand.
The son of a poor, widowed Jewish refugee mother brought up in government housing, Mr Key has made much of his humble origins.
He said when he entered parliament in 2002 that his mother had always taught him "there's no substitute for hard work and determination".
He came to politics late, winning his seat after a successful career in the financial markets that saw him become global head of foreign exchange for Merrill Lynch.
Just four years after taking his place in the chamber, Mr Key became leader of the centre-right National Party. By 2008 he had ended nine years of Labour Party rule, ousting then-prime minister Helen Clark.
He quickly demonstrated that behind the affable exterior was an acute political operator, a man who ensured the Nationals adopted moderate economic policies rather than the ideological campaigns against welfare and unions the party had pursued in the 1990s.
"What he has been able to do is demonstrate that if you make the case for reform, clearly cogently, persuasively, you can win and retain strong public support for economic reform," Australian Prime Minister Malcolm Turnbull told reporters on Monday .
Mr Key "has done an extraordinary job for New Zealand", Mr Turnbull added.
Arguably his finest moment came in the wake of a devastating earthquake in Christchurch in 2011 that claimed 185 lives, when his calm leadership helped settle a shocked nation.
"I've always been a glass half-full as opposed to a glass-half-empty (person) and the day that changes is the day I should leave," he said at the time. "So for me, I think that personality has helped in difficult times in New Zealand."
While there were missteps, notably a failed attempt earlier this year to ditch Britain's Union Jack from the New Zealand flag, Mr Key's approval ratings remained stubbornly high.
It was a characteristic that frustrated political opponents, including Internet mogul Kim Dotcom, who formed his own party in 2014 in an attempt to unseat the man he blamed for his legal woes.
"The prime minister could be photographed shooting little kittens in his garden with a shotgun and still be popular," the German tweeted after his bid floundered.
Even allegations of dirty tricks against members of his staff did not tarnish Mr Key's reputation at the last election, when the Nationals' campaign was squarely based on his personal popularity.
His departure robs the party of their main asset and throws the 2017 election wide open.
The centre-left Labour Party leader Andrew Little said he was looking forward to the contest, but understood why Mr Key was departing.
"Politics requires much sacrifice - we may all be politicians, but not all our lives are politics," Mr Little said.