Bill English quits. Now what?

National is about to take a huge step into the unknown. The phone lines are running hot, and MPs are doing the numbers, as the contenders line up to replace Bill English after his bombshell announcement that he was stepping down as leader of the National Party.

English broke the news to his stunned caucus 20 minutes into their regular Tuesday meeting, and left immediately after to prepare for a media conference.

There were tears from staff when English told them he was going and a steady trickle of MPs made their way to English’s office to pay their respects.For more than a decade National’s leadership has never been in question. Forget the faux leadership race in 2016 – ever since English stepped into Sir John Key’s shoes as prime minister, he has been the party’s most potent weapon.

English is National’s security blanket – the safe pair of hands, the steady influence, the man who got New Zealand through the dark days of the Christchurch earthquakes and the global financial crisis. He is the reason National’s support has held up in Opposition, even after Winston Peters threw them under a bus. Losing English could pull the rug out from under all of that – a potential throwback to the days of destabilising infighting, leadership spills and factionalism.

So why now?

Politics is brutal and no-one knows that better than English. When he quits Parliament in two weeks’ time, he will be a rarity in politics – a leader who left on his own terms.

If anyone deserves that, it’s English. He campaigned his heart out and on election night even outpolled the phenomenon, Jacinda Ardern.

But it wasn’t enough.

After the kick in the guts from Peters, it was clear English no longer had the fire in the belly.

He has served in two National governments and as Opposition leader twice. He’s survived treachery and betrayal from within his own caucus, yet remained intensely loyal to his party.

He came into his own as prime minister but it was as finance minister to Key that he earned his legacy and his larger-than-life reputation. Here and abroad, English and Key were the dream team, considered two of the most successful politicians of their time.

He has stamped his mark on the party in other ways. He was instrumental in softening the face of National, and shedding it of its flinty image. Even more so than Key, English will leave huge hole in National.

But the longer he stayed on as Opposition leader, the more his hard-earned legacy would have been eroded. The first signs of destabilising leadership talk had already surfaced – English’s state of the nation speech was overshadowed by speculation about who would replace him. The speculation was quickly squelched by a poll showing National still ahead of Labour under English.

But the die was cast; nobody expected English to stick around till 2020. The jockeying within caucus was now well under way.

It now emerges that English had by the time of the National caucus retreat at the weekend told his two lieutenants, Steven Joyce and Paula Bennett, of his plan to go.

The leadership race is wide open and the likely contenders are former cabinet ministers Amy Adams and Simon Bridges, who has raised his profile since the election and also happens to be a powerhouse fundraiser. The ability to bring money to the party should not be underestimated.

Deputy Paula Bennet will be doing the numbers, but her star is falling and she appears to be out of favour with the caucus.

Judith Collins is also a polarising choice among her colleagues and the public, but also has huge name recognition, so is seen as a contender, though behind Adams and Bridges.

Auckland Central MP and breast cancer survivor Nikki Kaye could have the same millennial cutthrough and profile as Ardern, but is not a caucus favourite.

Jonathan Coleman’s name has also been mentioned.

Wild cards include up-andcomers Mark Mitchell, Todd Muller and Alfred Ngaro but there may be a view in the caucus that the next leader should be a woman.

There will be a lot of calculation going on behind the scenes. However, some will be deciding whether it’s better to sit this one out. The next leader may struggle to get a honeymoon up against Ardern, especially with the huge attention her pregnancy will get. But Ardern taking time out for a baby may also be seen by some as an opportunity for the new National lineup.