Federal Health Minister Greg Hunt (Image: AAP/Luis Ascui)

On Friday, Health Minister Greg Hunt announced an emergency declaration under the Biosecurity Act, temporarily banning Australian citizens (and everyone else) from entering Australia if they have been in India in the previous fortnight. If anyone tries to circumvent the ban, they will face a fine of $66,000 or five years in prison.

Australia is the only country in the world that has attempted to prevent, by law, its own citizens from coming home — and the legal basis for this is in the act.

The Biosecurity Act gives incredible powers to the government once a “human biosecurity emergency” has been declared. Section 477 gives the health minister power to “determine any requirement that he is satisfied is necessary to prevent or control the entry of the disease into Australia”. This can include “requirements that restrict or prevent the movement of persons between specified places”.

The act requires Hunt to be satisfied that the ban is likely to be effective in or contribute to keeping COVID-19 out, that it is “appropriate and adapted” to the purpose, that it is “no more restrictive or intrusive than is required”, and that it will apply no longer than is necessary.

This power overrides any other law; meaning that the only other place we can look for moderation is the constitution.

But first, a distraction: Australia’s obligations under international law. Two Australian citizens stranded overseas recently applied to the United Nations Human Rights Committee (UNHRC) for an order requiring Australia to bring them home. They invoked Article 12(4) of the International Covenant on Civil and Political Rights, which says that “no one shall be arbitrarily deprived of the right to enter his own country”. Australia is a signatory to the covenant.

The UNHRC issued an interim order requesting our government bring the applicants home, pending a full hearing of the case. But here’s the problem: international conventions and covenants to which Australia is a party have no force under Australia law, unless they have been explicitly adopted by legislation here. The covenant has not, so the government can ignore it along with the UNHRC’s ruling. Which it will.

So, back to the constitution. It says nothing about Australian citizens’ rights. In fact it doesn’t mention the concept of citizenship at all. In 1901, when it was made, citizenship was still a fuzzy concept. More importantly, the Australian people were — both before and after federation — considered by law to be British subjects and nothing more.

But ask any Australian citizen whether they think they have an inalienable right to return home whenever they wish, and they’ll say of “course I do… don’t I?” The wording of the international covenant simply reflects what we’d assume anyway.

Therefore, it’s reasonable to read between the lines of the constitution and see if it confirms an implied right — in the same way the High Court says that it creates an implied freedom of communication on government and political matters, as an essential aspect of our system of democracy.

The question has never been considered by the courts, although there is a little bit of tangential support from a High Court case in 1988. This dealt with the validity of a law forcing airlines to pay an “immigration clearance” fee for arriving passengers, including Australian citizens.

The court, in passing, said that citizens have “under the law, the right to re-enter the country, without need of any executive fiat or ‘clearance’, for so long as he retained his citizenship”. Unfortunately, the judges didn’t mention which law. Unless it was the constitution, that law would be overridden by the Biosecurity Act anyway.

It may be that we have an implied right of return, as a necessary attribute of citizenship, which in turn is an essential component of our system of elected government — since citizenship carries both a right and an obligation under our law to enrol and vote.

If so, it’s unlikely to be held by the courts to be unlimited. They would accept that the return right, like all our other freedoms recognised by law, is subject to the government’s ability to make laws — within its constitutional powers — for the public good. It would be wrong to suppose that Typhoid Mary had an absolute right to fly home and get super-spreading without interference.

I do think, however, that there’s a solid case to argue that this ban on citizens returning from India is illegal. There are three parts to the argument.

First, that Hunt has misapplied his own power, because the blanket ban exceeds what is “appropriate and adapted”.

Second, that there is a right to return for Australian citizens, constrained by the power to impose restrictions only to the extent that they are necessary to protect the wider public interest. The Biosecurity Act gives the government many powers, including to enforce quarantine and even forcibly detain individuals to prevent or contain spread.

Third, that if the Biosecurity Act does allow this ban, then it is invalid because it falls outside the powers which the constitution gives to the Commonwealth Parliament. It’s not covered by the quarantine or immigration powers, so I can’t really see a constitutional basis for it at all.

It’s not hard to imagine measures the government could have spent the past year putting in place for such a contingency as this: that there are 9000 Australian citizens trapped in India, and they need to be rescued. It could be done.

Therefore, what the government has done is unlawful. Apart from being disgraceful. And racist.