The first, which played out on newspaper front pages over the past month, is the spat between (then) solicitor-general Justin Gleeson, SC, and Attorney-General George Brandis, QC. After challenging the Attorney-General over his lack of consultation on a direction affecting the solicitor-general's ability to give independent advice, Gleeson was drawn into an ugly political battle and ultimately resigned.

The second took place in early 2015, but was only brought to light last month after the release of correspondence between then Agriculture Department secretary Paul Grimes and his minister, Barnaby Joyce. In brief, Grimes notified Joyce that he no longer had confidence in his "capacity to resolve matters relating to integrity with [the minister]" after an incident related to amendments to the parliamentary record. "Hansard-gate", as it became known, involved allegations that Joyce misled Parliament and then had his office alter the record to disguise the deception. Grimes was sacked less than two weeks after sending the letter.

On one hand, both incidents occurred at a rarefied level and don't reflect the positions of ordinary public servants. The solicitor-general is an independent statutory officer with a range of rights and duties conferred by legislation, while the employment and termination of department heads is governed by a discrete part of the Public Service Act. More broadly, though, the two sagas highlight a concerning lack of protection for public servants who feel compelled to speak their mind on controversial and important topics.

In this column, I have long rallied against the attitude, seemingly prevalent among senior bureaucrats, in favour of creeping encroachments on public servants' free speech. Not only does the absence of strong protective mechanisms have adverse practical consequences for those who speak out, but perhaps more chillingly it creates a perception – exacerbated by these recent incidents – that dissent is not tolerated.

Robust debate, internal and external, is crucial to maintaining an accountable and effective administration and system of government. The Federal Court's Justice Paul Finn once observed, in a quote I cite with concerning frequency of late, "public servants cannot be ... silent members of society".

The current predicament was emphasised by recent changes in the ACT to legislation governing local public servants. These laws ban staff from behaving in a way that undermines the public service's reputation and requires staff to "dob in" suspected misconduct by their colleagues. While seemingly sound at first glance, the amendments were drafted so broadly as to potentially limit legitimate political criticism made outside of the workplace. The ACT then sought to defend the changes on the basis they were modelled on the APS code of conduct. One encroachment on free speech hardly justifies another.

Among an array of troubling developments in this space in recent years, the Federal Parliament's introduction of the Public Interest Disclosure Act represented an apparent bright spot. Designed to protect public sector whistleblowers, the legislation represented the culmination of almost two decades of progress towards that outcome. Independent MP Andrew Wilkie said during the second reading: "Officials must have the right to disclose misconduct, maladministration or incompetence, and communities must have the protection afforded by such outspokenness ... Those that would blow the whistle need to know they are doing the right thing and will ultimately be protected from reprisals. In essence, I think this bill does achieve that."

In practice, though, the scheme has had a less-than-triumphant impact. As I see regularly in my work, disclosures are too easily brushed aside or diverted. Data released in January showed that 40 per cent of all disclosures were never fully investigated. The lack of cases litigated to date under the act, which provides both a sword and a shield to whistleblowers, also limits an assessment of the effectiveness of these mechanisms. While obviously the same can be said of all new legislation, uncertainty as to act's operation in the judicial setting deters potential litigants from using this new statutory protection.

There's obviously a qualitative difference between sniping about disagreeable government policies on social media and engaging in heated public dialogue with a minister or raising integrity concerns with a superior in private. But all deserve protection. Otherwise, the public service risks becoming irreversibly politicised. It may seem paradoxical, but an apolitical public service requires a culture that accepts robust political debate within. If the present trend continues, those who are unwilling to toe the party line may find themselves surplus to requirements and those seeking to reveal politically distasteful misconduct or maladministration may be met with obstruction and retaliation.

The fates that befell Gleeson and Grimes – one pushed, the other shoved – might not immediately concern the average public servant. But the attitude among ministers that their cases reveal is a real cause for concern. Combined with the lack of adequate protections for those who wish to speak up, the Public Service Commissioner's call for greater courage among public servants begins to sound rather hollow indeed.

John Wilson is the managing legal director at Bradley Allen Love Lawyers and an accredited specialist in industrial relations and employment law. He thanks Kieran Pender for his help in preparing this article. john.wilson@ballawyers.com.au