The then secretary of the Department of Treasury, Dr Martin Parkinson, during Senate Estimates in November.

Treasury secretary Martin Parkinson during Senate estimates in November. Photo: Alex Ellinghausen

There can be few clearer signs that the Australian Public Service is, in an institutional sense, a gravely diminished institution within the structure of Australian government than the recent public lobbying - is there a more respectable word? - for retention of the head of the Treasury, Martin Parkinson.

The public/media agitation reached a peak on Wednesday evening when Ken Henry, Parkinson's predecessor as Treasury secretary, chose an interview on ABC1's 7.30 program to urge Parkinson's claims.

There is no indication that Parkinson is behind this public agitation and it is unlikely that he has any association with it. Such agitation would not become the dignity of any embattled department head. It is quite out of place when the head of the Treasury is concerned.

Despite recent amendments to the Public Service Act elevating the secretary to the Department of the Prime Minister and Cabinet, if only in salary terms, there is no more important post in the APS than head of the Treasury. There are some basic facts simply not amenable to statutory amendment.

The Treasury is, as Walter Bagehot so crisply put it, ''the fount of all business''. PM&C rather comes under the headings of publicity and public relations. (It resembles the Sitwell family, of whom it was said that they belonged more to the history of publicity than literature.)

The Treasury remains, in a significant sense, a conspicuously professional department. There is no more difficult post to fill in a modern public service than the head of the economics ministry. When there is a vacancy, even the long list of candidates is very short indeed.

There is, thus, much substance in concern about the uncertainty hanging over the job since it was announced last year that Parkinson would be leaving in the course of 2014.

But in addressing this matter, which has actually been dormant for several months, the agitators have not acted wisely in seeking to make the situation a public issue, especially as the objective seems to be to shore up Parkinson's tenure. As a tactic, it is likely to have a result precisely the opposite of that intended. It is an illustration that the traditional public service vow of silence, even if not a principle, is a cautionary rule of prudence.

Henry has hardly helped matters along with his particular approach. Parkinson's position has not been in question because there is some other ''more comfortable political character'' in the wings whom ministers are keen to move into his office; if there is, might not her or his identity by now be known?

For months before last year's election, there was much speculation about Parkinson's fate should the then opposition be victorious. The speculation certainly had nothing to do with his fitness for the post in terms of intellectual or technical qualification.

So far the Abbott government has looked to the public service for new appointees to head departments and the same is likely in the case of a Treasury vacancy. Time will tell.

And what of Henry's quoted claim, in this era of evidence-based decision-making, that ''no government has ever thought it appropriate to remove the head of the Treasury''? Has he no recall, even second-hand recall, of Gough Whitlam's bid to unseat Sir Frederick Wheeler in 1975, if necessary by translating him to the governorship of the Reserve Bank?

This has not been a state secret. Indeed, it was the stuff of dialogue at a prime ministerial press conference at the time.

And it is certain that, had Whitlam succeeded in removing Wheeler, his replacement could well have been ''a more comfortable political character''.

The Treasury's history is not as benign as Henry would lead his listeners to believe.

Departmental secretaries are the most important officers in the APS. They are, to adapt Bagehot's aphorism, the hyphen which joins, the buckle which fastens ministers to their departments. It is many decades since secretaries in the APS (even some Treasury heads) have been accorded the dignity inherent in their rank.

Their role and distinction has been weakened by the rhetoric of ''responsiveness'', now thankfully in retreat, and misconceived notions about the prerogatives of ''elected'' governments.

Were these matters not so serious, it would be tempting to conclude that top level personnel management in the APS derives more from Gilbert and Sullivan than the assured philosophies of Westminster governance.

J. R. Nethercote is adjunct professor, Canberra campus, Australian Catholic University.