Terry Barnes writes for the Australian edition of The Spectator, and advised Tony Abbott when he was a Cabinet minister in John Howard’s government.

There’s a photo taken in South Africa after Nelson Mandela’s funeral. Three Anglosphere Prime Ministers – Australia’s Tony Abbott, Canada’s Stephen Harper and New Zealand’s John Key –  were snapped in a restaurant, enjoying each other’s company and sharing their thoughts.  There was a fourth seat for David Cameron, but he was probably taking selfies with Barack Obama.

Then there were three.  After today, there are none.  Within weeks of each other last year, Abbott fell to a party room coup, and Harper was dispatched by Canadian voters after a disastrous general election campaign.

Until yesterday, just Key was left standing, unassailable.  No Opposition could touch him.  No scandal could mire him. Only Key could pull the plug on Key, and he’s done just that.  He said he’d seen other leaders staying on too long – he specifically cited Australia’s John Howard, who lost his seat in his 2007 election defeat – and he determined not to follow them, and not mislead the public about his intentions beyond next year’s general election.

As Key told New Zealand radio, he wanted to ensure a “transition to a new prime minister, without the baggage”. And as much as he loved his job, that is exactly what he’s done.

After a brief National Party leadership contest, he handed over yesterday to his long-serving deputy, Bill English – which means New Zealand remains in good hands.  English, the country’s Finance Minister, is a proven and prudent economic manager willing to take tough decisions for the greater good. While he failed as a first-term Opposition leader 15 years ago, he has grown in office as a minister, Deputy Prime Minister and a respected figure in the international economic community.

As Tim Montgomerie highlighted in his analysis of Key for ConservativeHome, Key and English have made New Zealand a success story since 2008 that Britain, Australia and Europe have much to envy.  They’ve won three elections on the trot, and dominated their Parliament, despite being in permanent minority government thanks to New Zealand’s German-style electoral system.  They successfully introduced and implemented significant but electorally-challenging economic, welfare-to-work and social reforms.

Above all, while Britain and Australia are resigned to budget deficits as far as the eye can see, this year New Zealand reaped the dividends of the Key-English taxation and spending reforms, and got its budget back into surplus, notwithstanding the challenges of the global economy and the necessity of funding massive reconstruction after the 2011 Christchurch earthquakes.

Indeed, thanks to his and English’s prudent work on economic management and reform, Key could commit billions to the Christchurch rebuilding effort without damaging the wider Kiwi economy.  English is the chief architect of this fiscal and economic success and, though lacking Key’s charisma and personal popularity, his economic record is both his claim to leadership and his biggest electoral asset.

English, however, is not the only figure who can share credit for Key’s success.  Behind the scenes, Key has been ably assisted by a chief-of-staff who came from business – Wayne Eagleson, who understands the importance of building coalitions and maintaining less adversarial relationships with the Opposition, minor parties and giant egos such as Winston Peters, the leader of the populist but electorally-crucial New Zealand First party.

An avoider of limelight, Eagleson is less a command-and-control gatekeeper and more a facilitator and supporter for ministers, staff and MPs.  Key’s office has been a happy and accessible one, reflecting Key and Eagleson’s “we’re here to help you, not tell you” leadership style. It is well-respected across the political spectrum, and that Eagleson is staying on to lead English’s office will give New Zealand’s business and foreign trading partners confidence in the transition, and help English and National to gear themselves for next year’s general election.

Eagleson’s management style, and the way he coordinates and guides ministers rather than commands them, has maximised performance and harmony, and minimised internal tensions and policy confusion.  As the May Government struggles to look as though it knows what it’s doing on Brexit and other policy, and seems to have adopted an unofficial “bash Boris Johnson” policy, May’s joint chiefs-of-staff, Fiona Hill and Nick Timothy, would do well to consult Eagleson about his and Key’s success in running New Zealand’s government and keeping it unified. Indeed, May should keep Key’s number on speed dial for his political advice.

It’s very rare to see a PM depart at the height of their powers: most go from electoral defeat (David Cameron’s post-Brexit vote departure should be classed as such), or from losing their party’s confidence.  Former currency trader that he is, Key chose his own time of leaving, perhaps sensing that after eight years it was time to “sell” his political currency before its value declined.

The risk now for the National Party is that Key’s remarkable personal popularity kept his government utterly dominant over the Labour and Green parties in electoral support.  Dour South Island farmer English is no extroverted Key: to win his party a fourth term, he will need to rely far more on his policy substance and good management, not personal style.  But in his favour, the New Zealand economy is sound, the inevitable ministerial reshuffle will refresh a generally solid frontbench team, and the Labour Opposition drifts, having had four lacklustre leaders since losing office in 2008.

Australian Liberals admire and envy Key as the sort of able, managerialist but electorally-aware Prime Minister we haven’t had since Howard departed.  In Britain, Conservatives too should look to Key, draw lessons from his policy and political successes, and apply them: simply assuming having a rabble for an Opposition inoculates a Government from its own inadequacies and divisions is a recipe for ultimate failure.