If, like most Australians, you’ve never read the Australian Human Rights Commission Act 1986, you may be surprised by how wide it is. The act establishes 15 separate functions and roles for the commission to carry out (plus a 16th “anything incidental” function), ranging from handling discrimination complaints, to conducting inquiries into human rights breaches, to vetting legislation, as well as an advocacy role.

The Australian Human Rights Commission has a function to “promote an understanding and acceptance, and the public discussion, of human rights in Australia”, “undertake research and educational programs”, and “on its own initiative or when requested by the Minister, to report to the Minister as to the laws that should be made by the Parliament, or action that should be taken by the Commonwealth, on matters relating to human rights” — including in relation to Australia’s adherence to international agreements on human rights.

As Crikey argued in 2013, the AHRC’s advocacy role is the one that is most problematic, nebulous and unrestricted. It requires the commission to be selective about what it advocates for, because it can’t effectively advocate for everything in the broad remit of human rights at the same time. But neither the Coalition nor Labor has proposed to amend the AHRC’s functions. So, in the absence of other evidence, notionally the two major parties support this wide-ranging advocacy role — including the role of reporting on what actions the Commonwealth should be taking in relation to human rights.

And it’s the legislated duty of the commission to ensure that those functions are performed “(a) with regard for (i) the indivisibility and universality of human rights; and (ii) the principle that every person is free and equal in dignity and rights; and (b) efficiently and with the greatest possible benefit to the people of Australia.” As the senior member of the commission and the accountable authority of the commission, AHRC president Gillian Triggs has a statutory responsibility to carry out that duty.

The government’s ceaseless attacks on Triggs are, therefore, literally for doing her job, a job that she is required by law to do, a job that the government has elected to leave defined in its current, very broad form.

As several commentators have noted, the government’s latest attack on Triggs is factually wrong. Attorney-General George Brandis and Immigration Minister Peter Dutton tripped up last week in accusing Triggs of using a speech to link the government’s efforts to turn back asylum seeker boats with Indonesia’s decision to execute Andrew Chan and Myuran Sukumaran. Triggs had done no such thing. Instead, she had linked the government’s campaign to turn back boats — which led to repeated infringements of Indonesian sovereignty — with Indonesia’s refusal to engage with Australia on efforts to abolish the death penalty. Even a quick Google of Triggs’ advocacy in relation to the death penalty would show she has been calling for a regional moratorium on capital punishment and even suggested linking aid to the moratorium.

Brandis and Dutton are two of the most incompetent ministers in a dreadful government. Brandis had previously used his department head Chris Moraitis to approach Triggs with a job offer to convince her to resign. Brandis’ most recent debacle was to accuse Labor of inappropriately questioning his handling of a letter from Man Haron Monis — just weeks before the Lindt Cafe Sydney siege — before having to admit he had falsely claimed to have passed the letter to the government’s inquiry into the siege. Dutton was dumped from the Health portfolio for (to use the words of Tony Abbott himself) “mishandling” the GP co-payment. On the weekend, Dutton pretended high dudgeon over Triggs’ remarks and used a grovelling interview with far-right media personality Andrew Bolt to suggest she resign.

However, last week, Triggs did take up an issue that places her in direct opposition to not merely the Coalition and Labor, using another speech to criticise the growth in executive power at the expense of parliamentary and judicial oversight.

Since the Keating years, there has been a steady expansion of executive power in the Immigration portfolio and a reduction in opportunities for judicial oversight. Much of that shift was appropriate: the refugee application system was ruthlessly gamed by illegal immigrants in the early 1990s, with hundreds of appeals clogging up the Federal Court. In response, successive governments have significantly curbed the capacity of courts to exercise any power by way of a merits review over decisions by the Immigration minister. This government has gone further and curbed parliamentary oversight of Immigration matters, pretending that asylum seeker boats were a military threat and declaring anything relating to efforts to turn them back must be kept secret even from traditional forums for bureaucratic accountability, like estimates committees.

Now the Immigration department is at the centre of another effort to dramatically expand the powers of the executive, with the government’s proposal to strip the citizenship of both dual nationals and anyone who could potentially claim dual citizenship purely on the Minister for Immigration’s say-so, without any merits review by a court. As the reaction of former immigration minister Amanda Vanstone suggests, such unchecked executive power is a direct affront to traditional liberalism.

Under the proposal, Dutton would be given the power to declare that Triggs, who was born in the UK, was negligently aiding terrorism through her advocacy of human rights (or perhaps he might read a misrepresentative article about her statements in The Australian and decide she was actively supporting terrorism) and strip her of her citizenship. There’d be no judicial review of such a decision, however ill-judged.

Don’t think it will happen? Probably not to a high-profile figure. But Immigration is the portfolio that sent Vivian Solon to the Philippines and locked up Cornelia Rau without any legal right, and which presided over the sexual abuse of children on Nauru but insisted it knew nothing about it until late last year. A negligent department led by an incompetent minister demands judicial and parliamentary checks. That the Liberal Party needs reminding of this fact demonstrates just how illiberal it has now become.