The evidence about the conduct of senior Commonwealth public servants provided to the Robodebt Royal Commission is both astonishing and disturbing.

A little over 30 years ago it was my job as the National Affairs Editor on The Canberra Times to cover the Australian Public Service (APS) and it is safe to say that the type of conduct alleged against senior public servants, including former head of the Department of Social Services, Kathryn Campbell, would have seen heads roll.

But, of course, 30 years ago the APS worked to a more traditional model within which career public servants understood it was their role to provide frank and fearless advice to the Government of the day and department secretaries, the “mandarins”, vigorously defended their right to do so.

Thirty years ago there existed a pool of highly experienced senior public servants from which new Governments could appoint new department heads without tainting the “frank and fearless advice” mantra by resorting to external, political appointees.

That changed significantly in 1996 when then Prime Minister, John Howard appointed Max (‘Max the Axe’) Moore-Wilton to the key role as secretary of the Department of Prime Minister and Cabinet.

Moore-Wilton had spent time in the Commonwealth and NSW public services prior to his appointment to head up PM&C, but he was certainly not a Canberra public service senior insider and he was certainly perceived at the time as having a political philosophy aligned with that of the incoming Howard Government.

Moore-Wilton distinguished himself in the opening year of his appointment by overseeing the reduction of thousands of jobs in the APS.

While Moore-Wilton was succeeded in PM&C by a career public servant in the form of former Public Service Commission chief, Peter Shergold, his tenure at the helm of PM&C between 1996 and 2002 is widely regarded as having been influential in changing how Governments appoint public servants.

So, for many veterans of the Australian Public Service there will be sage nods at the evidence provided to the Robodebt Royal Commission from former Department of Human Services secretary, Renee Leon, that some secretaries who did not comply with the minister’s requests were “completely on the outer”.

“I know one secretary that resigned in such circumstances,” Leon told the Royal Commission. “Ministers would tell secretaries to move deputy secretaries to other roles if they were perceived to be unhelpful, even though the minister is supposed to have no say.”

“So, it wasn’t popular to give the government advice that what they were doing was wrong.”

For the record, the former secretary of the Department of Human Services, Kathryn Campbell, does not fit the usual mould of career public servant, having entered the Australian Public Service after a distinguished career in the Australian Army Reserve where she rose to the rank of Major General.

It is worth considering that Campbell was succeeded as secretary of the Department of Social Security by former vice-admiral Ray Griggs.

Not being a career public servant should not preclude talented and highly qualified people from heading up Government departments, but their value to tax-payers is diminished if they cannot or will not deliver frank and fearless advice.