God loves a trier but unfortunately the Prime Minister does not feel the same way about his latest trier - Tau Henare.
Henare has put his name forward to be Parliament's Next Top Speaker. He announced his intentions on Twitter and then to the media. Key was in Japan at the time, but the "pfffst" of breath that indicates a disturbance in the Prime Ministerial pond of tranquillity was audible from New Zealand.
Without saying it out loud, Key made it perfectly clear Henare was the Eric the Eel of the race to be Speaker.
Rather than subside quietly back into the green leather of the backbenches, Henare showed he had learned something from the Prime Minister - optimism.
He set out his qualifications - chairing a select committee, five terms in Parliament in both a small and a large party, time as a minister, and as both an electorate and a list MP. Empathy with the naughty is not usually on the list of skills required for Speaker - but Henare made a virtue out of vice, pointing out his own bad behaviour had given him a breadth of experience other more restrained contenders lacked.
By the time his pitch was done, he had cast himself as the Princess Diana of Speakers - the People's Speaker, pledging to "take the House of Reps out to people a lot more".
Key set out two criteria to be the Government's nomination for Speaker. The first was that Key had to be confident the person could do the job. The second was that the new Speaker had to be acceptable to most - if not all - other parties in Parliament.
It was clear he considered Henare did not meet the criteria, not least because even the Prime Minister has to do what the Speaker orders in Parliament - and Key would not be alone in finding it difficult to be bossed around by Henare.
What is often forgotten was that Lockwood Smith was only a second choice Speaker back in 2008 after United Future leader Peter Dunne refused it. Further, Smith failed the second of Key's criteria: he was nominated fresh off the "small Asian fruit-picking hands" debacle during the 2008 election campaign. He was regarded as one of National's right wing ideologues and there was significant disquiet from Labour about his ability to be non-partisan as Speaker. At the time Trevor Mallard described the possibility it would be Smith as "laughable".
Henare's argument is that he too will emerge from the chrysalis of his renegade days and put the days of brawling in lobbies and heckling behind him.
At the moment, the Prime Minister and the backbench MP are in a game of chicken. The Prime Minister has the distinct advantage, of course, in the way an elephant does in a body-slamming competition with a mouse. But he also has to be careful.
Blogger and National supporter (and critic) Cameron Slater sees the subversion as the thin edge of the wedge as backbench MPs start to tire of waiting for their turn to sup the nectar of incumbency.
There is some truth to that and Henare was always likely to be among the first to pop. He had tasted power in the 1990s as a minister with NZ First. There was undoubtedly some thwarted ambition behind his bid - as well as residual bitterness and concern about 2014 after being dumped unceremoniously down National's list rankings in 2011.
He has remained admirably loyal to Key since then. But if Key cuts him off too brutally, he risks pushing Henare further into open defiance by refusing to withdraw from the race. That is dangerous territory for both.
It doesn't help Key that his own choice, David Carter, doesn't seem to want the job. Carter's reaction makes it clear the traditional show of reluctance when a new Speaker is dragged to the Chair will be more than just a show.
And like Eric the Eel, Henare has started to get some underdog support and even some grudging admiration from his colleagues for having the guts to give it a go.
Politics watchers enjoy a contest, even when the outcome is obvious. In this contest, while it is still unclear who will be the next Speaker, it is clear that it will not be Henare. But should Henare stay the course, it will at least provide six months of entertainment and "pffsts" from Key before the matter is actually settled.