Duncan Garner: The John Key I knew - a kooky assassin

John Key (AAP file)
John Key (AAP file)

OPINION: He was without doubt New Zealand's most popular Prime Minister ever.

But today, John Key stood down in a shock move and the country will have a new leader from next Monday.

To go out with National still close to 50 percent in the polls is almost too good to be true. But it is true. Key has been remarkably popular.

I'd go further and say he was a populist phenomenon - a political tsunami who couldn't be stopped at times. He was the anti-politician that New Zealanders quickly warmed too.

They didn't mind the cringe moments - they knew he was smart. And, crucially, he was likable.

But Key's shock resignation is also National's nightmare scenario and it will be a dark day behind closed doors. 

Who is our next PM? They're in the job from next Monday night.

The smart money is on a managed handover to Bill English, with Judith Collins probably keen in the background. How will she play this? Is she too risky? Is she rehabilitated? Next Monday we will know.

But English will want this. 

He's always wanted it and he's been unwaveringly loyal to Key. He's waited for this day. 

Paula Bennett may have to wait a bit longer. I thought Key might back her, but it's clear he has thrown his weight in behind English. That's bad news for Bennett. She may have missed this bus.

Then there's Labour. They should be wishing Key well and thanking him for this decision.

And that's because Labour will come off eight years on life-support as of today.

This is genuinely massive for the opposition. They have a much better chance now that Key, the unmovable road-block, has moved himself out of the way.

I remember Key stood out when he arrived in Parliament back in 2002.

He was smart and ambitious. He never came to be a backbench MP.

He was a great learner and listener. He took advice and then did it his way. 

I had a night out drinking with him as opposition leader. It was like drinking with your uncle. 

He was politically naïve and, in many ways, he was kooky. He was also smart and immensely likable.

But had another streak - I thought he was determined and seriously focussed on the prize, like a silent assassin.

There are no big legacy projects you can point to and say Key did that. 

But his legacy is his popularity and economic stewardship. His oversight of the economy was second-to-none.

I also know that Key hated the thought of losing, or even a single poor poll. He's that competitive and that forensic about numbers.

Now he's over the hump there is only one way - and that's downhill. The good times have been had and the tread is coming off the tyres.

He doesn't want to be there to lose. Someone else can take that hit.

In many ways he's been a remarkable Prime Minister, with economic challenges and disasters both natural and man-made thrown at him. 

On his way out Key said a "good leader knows when it is time to go".

I respect that. Too many politicians hang around, take the pay and eat their lunch.

Key was not one of those people. He's a winner and he knows how to go out.

If I have a criticism, it's this - Key had so much political credit, but he didn't always spend it.

He could have done so much more with the support he had.

But there is also the saying: "Leave them wanting more."

Key did just that.