A Wellington MP of more than three decades standing, he has long positioned himself where he thinks the centre of the political spectrum is located, even though most observers would place him far closer to National's hegemonic grip on the centre-right.
Still, it is a vantage point which enables Mr Dunne to flail both to the left and right of himself.
But occasionally he likes to use that positioning as some kind of justification to claim a role as some kind of a neutral referee of political proceedings.
It may be his formative days as student politician while completing a master's degree in political science that persuaded him he could simultaneously be both partisan participant and objective observer of politics.
More is the pity that the latter role seemed to go into rather sudden hibernation during and after an investigation into the unauthorised leaking of a highly sensitive report on the performance of and working conditions in the Government Communications Security Bureau to a senior journalist in the parliamentary press gallery - and which resulted in the prime minister dumping the leader of what remains of his United Future Party from his job as a minister outside the Cabinet, if only relatively briefly.
Whatever, the far more impartial Mr Dunne was to the fore this week offering some guidance on the latest hot topic, or very much so a reheated topic, which will command a fair chunk of his and his fellow parliamentarians' attention for the next year or so - namely the so-called ''end-of-life'' debate.
Mr Dunne devoted his weekly blog, Dunne Speaks, to the highly vexed matter of ''death with dignity'' or ''doctor-assisted suicide'' - or whatever euphemism you prefer to use in place of the instantly blood-chilling ''voluntary euthanasia''.
The two words combined may sound awfully Orwellian. But they are a reminder it is not going to be a lot of fun watching the plug being pulled on granny no matter how much she might be pleading for that to happen.
While Mr Dunne believes that ''doctors should not be able to kill terminally ill patients'', the increasing complexity of end-of-life care is seeing medicinal advances prolonging life to the point where some patients are no longer living a natural life. These increasing complexities are starting to seriously undermine the ''absolutist'' stances of those who hold sway at the two extremes of the arguments surrounding voluntary euthanasia.
With such a highly charged, emotionally draining matter having been plonked very firmly back on the political agenda - largely as the result of Lecretia Seales' very public plight and failed fight in the High Court for the right to die - Mr Dunne is suggesting that some kind of eminent persons group, perhaps even a royal commission, should be established to conduct a wide-ranging inquiry with - and this is crucial - the Government being obliged to implement the key recommendations.
National has so far only offered a pale imitation in the form of a select committee inquiry, the recommendations of which it can ignore or shelve.
Even if Parliament's health committee comes up with a draft Bill, the only way it can be introduced into the House without relying on the unlikely prospect of securing a slot on Parliament's order paper via winning the Lotto-like ballot of private member's Bills is either by leave or as a Government Bill.
John Key has made it pretty plain he is not willing to countenance the latter, while it only takes one MP to refuse to grant leave to block a Bill from making it on to the table in the House.
Further complicating things is that the chairman of the health committee, Simon O'Connor, is an ardent and active opponent of voluntary euthanasia. While he will have to be bias-free during the inquiry's proceedings - and most MPs are confident that he will be - it is difficult to see him putting his name to a report which authorises the practice, regardless of how many safeguards are written into the legislation.
That raises the prospect of the committee producing both a majority report and a minority report - something which would weaken any mandate for change that might flow from public pressure contained in submissions to the committee.
That pressure - if there is any beyond the confines of the respective pro and anti lobby groups - needs to be harnessed if the ban on assisted deaths is to be axed.
The other glaring absence is the failure of some MP to come forward and be the face of change.
That is not surprising. Shepherding a private member's Bill through Parliament on conscience votes requires a huge degree of commitment, energy and perseverance even for a simple measure.
Even if a Bill managed to make it on to the floor of the House, there is of course no guarantee it would get the numbers to make it into law.
The large ratio of National MPs to Labour's means this Parliament is more conservative in composition. What seems odd is that Parliament has long been out of kilter with public opinion on this particular conscience issue. Opinion polls have consistently shown that between 60% and 70% of the public back voluntary euthanasia. But two private member's Bills brought before Parliament during the past two decades both failed to make it even to the select committee stage.
The reason is that MPs worry about the 30% to 40% who are opposed. The problem - as others have noted - is that there is absolutely no middle ground with this issue. You either back it or you don't. Terminally ill patients can't be half-dead or half-alive. There is no halfway house of compromise which offers MPs the safety of their avoiding what is ultimately a life or death decision.
- John Armstrong is The New Zealand Herald political correspondent.
