The renewed controversy over public servants' rights to freedom of speech, and government efforts to define and limit those rights, is not the simple matter it may seem at first glance. While many people rushed to pillory the Coalition last week, this issue is not about politicians' attempts to muzzle criticism.

Rather, it begins and ends with the bureaucracy itself. Senior public servants, not parliamentarians, are the ones who are seeking to mute staff's political views. Nor are the Australian Public Service policies that govern staff comments limited to suppressing criticism of the Abbott government, as has been widely (and wrongly) reported. The rules are far broader, applying to criticisms of any politician, political party or policy. Indeed, they were put in place under the former Labor government, not by the Coalition.

The latest arguments began when the Department of the Prime Minister and Cabinet told staff to inform on colleagues who expressed strong political views on Facebook, Twitter and the like. Public servants know, when they begin their career, that their vocation is unlike others. They serve the will of the community as expressed by the elected government and the public rightly expects that they will advise on, develop and implement policies with strict neutrality, regardless of whether they personally agree with those policies. Indeed, the law obliges public servants to carry out their work in an apolitical and impartial manner.

These expectations are uncontroversial and have been for the better part of a century. Public servants always knew that, so long as they exercised discretion and acted professionally at work, they were free to be politically active in their private lives. They could join political parties, write letters to newspapers (providing their comments did not touch on their own area of work or disclose confidential information) and even hand out flyers for their preferred parties on election days. There was certainly nothing wrong with them voicing their opinions at, say, a barbecue or a dinner party.

Yet that is, in effect, what the bureaucracy is seeking to outlaw. The Public Service Commission and most other government workplaces now warn staff they may breach the Public Service Act if they post a ''harsh or extreme'' political comment online, regardless of whether it is made on a closed, private website or even whether the comment is made in the employee's real name. The stated justification is that online comments are different because their potential audience is far greater. Yet this ignores the more important question: what evidence is there that a public servant's personal opinion can undermine the integrity and reputation of the APS? Surely, an individual's opinion is of little or no consequence and need not affect their work in any marked way. Yet the public service's default position is that any strong political view is a potential danger. This moral panic is clearly absurd; nonetheless it is now policy.

Most public servants may well feel unaffected by this debate. They no doubt take care to refrain from expressing views that may worry their managers. Yet this matter speaks volumes about the public service's oversensitivity to risk and its unnecessarily closed approach. While many other Western bureaucracies are embracing the innovation and genuinely open government that the internet allows, the APS retains the secretive habits it inherited from Westminster. (For another example, one need only consider its recent, blighted record on freedom of information.)

Last month, the Immigration Department settled out of court its dispute with its former employee, Michaela Banerji. It had sacked Ms Banerji after she used a pseudonymous Twitter account to regularly criticise refugee detention policies. In earlier court hearings, Ms Banerji had argued that the bureaucracy's social media policies encroached on her freedom of political expression, which the High Court has previously found is an implied right in the constitution.

It is shame, in some ways, that Ms Banerji's case ended without a thorough examination of that argument. The legality of the APS approach will remain clouded until a similar case arises and the court considers it in full.