A long-standing principle in Australian politics, one derived from Westminster and British experience over hundreds of years, is that incoming governments do not use the confidential discussions of cabinet proceedings to seek to embarrass the losers of the last election.

There are good reasons for this restraint. In cabinet, any government needs ministers who will speak fearlessly, who will be totally open in what they say, on whatever subject is under discussion. It can be a sensitive matter on foreign affairs; there might be significant criticism of a close ally. Criticism between ministers can sometimes be acute.

It is important that freedom and openness remain part of cabinet discussions. It is important that all points of view are exposed. Ministers should not have to look over their shoulders and wonder, how will this look when the next government publishes what I am now saying?

What is the royal commission’s purpose?

I have seen the letters that passed between shadow attorney-general Mark Dreyfus and attorney-general George Brandis. The implications are clear. The papers relating to the so-called “Pink Batts Affair” have already been passed to the Royal Commission into the Home Insulation Program.

If the royal commissioner wishes to publish some parts of those papers, or all of them, the government will at that point decide whether it wishes to claim immunity or not. Apparently, prime minister Tony Abbott directed that the papers be made available for the royal commissioner earlier this year, without the knowledge of the attorney-general.

A number of questions arise. What is the purpose of this royal commission? I know it was promised before the election, but the question still remains, for what purpose?

Royal commissions are generally designed to lead to significant government action and sometimes to prosecution of people found guilty of an offence. What can come out of this royal commission? Is there any suggestion any member of the previous government will be prosecuted?

There have been coronial inquiries in New South Wales and Queensland into the four unfortunate cases that led to deaths. The cause of death is known. Three of the four employers have been prosecuted and convicted.

The royal commission will learn nothing new of those circumstances. It was a badly run industry – if you like, an incompetently run industry – without adequate supervision, training or control.

Most people would regard the government management of the program as incompetent, as one of the reasons that led to the defeat of the Labor Party. I suspect it is likely, even probable, that the royal commission will confirm that view. Does the government believe this will have a significant impact on the next election?

Such a view is not particularly relevant. The major players, former prime ministers Kevin Rudd and Julia Gillard, are no longer in parliament. There will be other issues far more important in people’s minds than this old and buried Home Insulation Program.

Does the government believe the royal commission can lead to prosecution of ministers? That is most unlikely. It would seem, therefore, that the process is political and designed to be so.

This is likely to have continuing adverse consequences. When the current government loses, as one day it will, an incoming Labor government will be under significant pressure for a payback. It is too early to tell what issue they might pick, but there will be one.

Are we to begin a cycle of royal commission after royal commission trying to expose the ills, the mismanagement of actions, of the previous government? Ministers would be much more careful of what they say in cabinet. Both consequences would have adverse impacts on Australian democracy.

The issues are not complex; they are clear. Cabinet confidentiality ought to be maintained. It is central to our system of government. The papers ultimately become public, but after a significant time has elapsed.

The need to protect the body politic

This latest government action could have other even more adverse consequences.

In 1975, a private prosecution was launched against former prime minister Gough Whitlam, attorney-general Lionel Murphy, Rex Connor and Jim Cairns. There were suggestions that the government should take over that prosecution.

One of the commitments I had given the governor-general at the time, if I was asked to form a government, was that there would be no pursuit of possible illegal actions of the then government through the courts. I had no hesitation in making such a commitment. Again, for good reasons.

On a number of occasions in British history a prosecution has not been launched because it would do damage to a body politic as a whole. While clearly the chief law officer is the final determinant of whether or not a prosecution should be launched, the chief law officer in our system is also a member of cabinet and would be wise to listen to the advice of senior colleagues.

If my government had taken over the Sankey prosecution, it would have been extraordinarily divisive. There had been an election. People had paid a heavy political price for their actions. There was no crime against the Commonwealth, as the judgment in the private prosecution by Sankey ultimately demonstrated.

Whatever errors were made were political and a political price was paid for those errors. If a prosecution had been launched, the divisions within Australia, which were sharp, would have been so much greater. That was to be avoided.

Launching a prosecution against a defeated political foe is only one step further than launching a royal commission against that political foe. Indeed, it can be argued that having a royal commission is designed to prepare the ground for launching a prosecution. That would compound an extraordinarily bad decision, which defies over 113 years of Australian history and a much longer period of British history.

The issues are intertwined: the question of cabinet confidentiality, releasing papers to the royal commissioner, and the question of pursing a political foe through courts of law. This is not a question of putting anyone or any organisation above the law. It is a question of what makes democracy work well or extremely badly.