Cementing the National Party in the political centre – that is John Key’s major challenge in building a government capable of taking New Zealand through the recession and back to health. Reaching out to Maori is a good start.

John Key has made a couple of hard calls that signal he is not going to be Mr Flip-Flop in government.

It was zap to Winston Peters before the election, and zip for Roger Douglas after it. Key has driven home an important message: The incoming government will focus single-mindedly, without distractions, on delivering solutions to critical core problems, such as jobs, health, education, law and order, and recovery from recession.

Key was under pressure from the moment he made it crystal clear, at considerable risk, that he would not have Peters or Douglas at the Cabinet table in any government he led.

As Peters survived inquiries by the Serious Fraud Office, the Electoral Commission and the Police, the press gallery reef-fish gathered in support of Helen Clark’s position: wait for due process to take its course.

Due process concluded that Peters would be not prosecuted – but that is no guarantee of fitness to hold ministerial positions where evident integrity and accountability are needed to secure the trust of coalition colleagues and voters in times of tough decisions.

Key is right. The Peters penchant for double-speak instead of straight talk, for getting into ambiguous relationships with rich favour-seekers, for conducting a love-hate relationship with the media to keep himself in the spotlight, and for playing a highly opportunistic brand of niche politics at the expense of coalition unity would distract and destroy any new government he joined.

Look what Peters did to the Labour-led coalition. More than anyone else, he eroded Helen Clark’s reputation for effective coalition management – and the very basis of her “trust-me” campaign.

The New Zealand First leader thumbed his nose at the suggestion his party should join Labour and all other erring parties in repaying Parliamentary Services funds that were drawn for unauthorized electioneering purposes in 2005. He undermined the effort to achieve broad support for a workable reform of election funding practices by fanning new fire from the embers of old conflicts. When those fires blew back on him in a series of controversies about his own party’s funding practices, he aggravated the situation by moving into aggressive denial.

Helen Clark seemed incapable of applying the same discipline to Peters that she had previously shown in a string of controversial situations that had resulted in Labour ministers and senior public servants being sidelined, disciplined or sacked for their troubles.

Clark had the opportunity to scotch the funding furore between Peters and his Labour-loving supporter Owen Glenn at the start of this year, but she could not bring herself to crunch the conflicting accounts of the “two honourable gentlemen” over their dealings with each other.

When Peters finally advised her that his lawyer had received a donation to his legal defence fund from Glenn without his knowledge, the prime minister sidelined herself and left it to her Minister to address the matter in public.

She could have used her capacity, under the terms of the Cabinet Manual, to require her embarrassed and embarrassing minister to return the gift to its donor, Clark chose not to do so on the basis of a very peculiar piece of advice from her officials: “The Cabinet Office advised me that the court case, of course, was one of particular public interest—considerable public interest—and in such circumstances, if, and I underline that word, such a sum of money were deemed to be a gift, there would be no reason to require a Minister to relinquish it.”

Of course the donation was a gift. The claim that it funded a case “of particular public interest” is unsustainable. An electoral petition to overturn the Tauranga result in 2005 was a case of particular political interest – to New Zealand First and Labour.

The drawn-out combination of public denials and backroom shenanigans over Glenn’s donations and his ambitions for a diplomatic appointment became a fatal distraction for Clark.

Trust in the “strong and proven leadership” of Helen Clark and Winston Peters, New Zealand First and Labour, diminished to the point where voters determined last weekend that their essential partnership in coalition government was no longer viable.

John Key should keep this experience firmly in mind as he proceeds with the formation and conduct of his own coalition. In post-election dealings with ACT, he acknowledges the destructive power of ill-disciplined mavericks.

Roger Douglas was prepared to see a government destroyed rather than compromise on a free-market ideology that no longer commanded support among his political colleagues. The world has changed since the 1980s – but Douglas has not. Outside or inside the tent, he will be seen as part of the old problem, not part of the fresh solution. Key shows wisdom in reaching out in a new direction - to the Maori Party.

It seems unlikely that his overture will result any formal coalition commitment in the near future. However, Key has the capacity to secure trust over time – if he stays true to his original course of building relationships beyond his natural constituency and continues to listen to new Maori voices who share his belief that change is needed to advance the interests of all New Zealanders.