Sophisticated facial recognition technology now exists which could, for example, identify a would-be terrorist scouting a site for an attack.

On the one hand, there is a very understandable inclination to allow law enforcement to use every technology available to keep us safe. On the other, there is the need to protect citizens’ assumed right to move with privacy and freedom through public spaces.

It is of great concern to learn that law enforcement and government agencies want to be able to collect and share this data among themselves, particularly as who will be able to access that data and how they will be able to use it has not been clearly defined.

It is unacceptable to assume the majority of Australians, who aren’t criminals and have the expectation to be kept safe by the state, are willing to succumb to heightened surveillance.

The question of what is an acceptable cost to Australians is something the Law Council of Australia has posed to the parliamentary committee examining Home Affairs Minister Peter Dutton’s  Identity-matching Services Bill.

This proposed legislation would see the government, through the Department of Home Affairs, launch a nationwide facial recognition system. Essentially, it would allow a broad range of government agencies to spot “a face in a crowd” and share that information among themselves.

Biometric identity is not limited to facial recognition – that is just the first iteration. It also includes iris and retina recognition, plan vein recognition, even sweat pour analysis and body odour recognition.

The minister has a rule-making power that could expand beyond just facial recognition.

The government, and potentially non-government agencies, would also be able to verify identities. States could share biometric information and use it to detect multiple drivers licences or other ID documents.

This Identity-matching Services Bill would be linked to the Passport Act, allowing government and law enforcement agencies to share travel data at a national, state and territory level.

Some might well deploy the line that if you’ve done nothing wrong then you have nothing to hide. But this argument oversimplifies the important social compromise we, as citizens, make between privacy and safety.

It’s all very Orwellian, quite frankly.

If citizens agree to give their data for one reason (such as for a biometric passport) and then have it used for an entirely different purpose, like a digital line-up, to what are we actually consenting? We don’t know.

Are we really okay with the notion that executive power is devolved to an algorithm, a machine, and the possibility that its capacity for error can result in an entirely innocent person being placed on a watch or suspect list?

While the proposed system has been described as a “hub and spoke model”, the nature of the hub has no detail around it in the Bill.

So, what are we giving our identities up to? The answer is something yet to be designed by the “secretary” of the hub. It’s all very Orwellian, quite frankly.

The government says “just trust us”, yet the experts warn that creating a central intelligence hub will make us vulnerable to foreign actor hacks.

Without being paranoid or conspiratorial, we must nevertheless be wary, or at the very least conscious, of the implications of giving authorities further access to our private lives.

Identity-matching services are legitimised through public trust in what governments are doing. That trust is hard-gained and, in today’s world, easily eroded and hard to regain.

The inclusion of “robust privacy safeguards” within the intergovernmental agreement reflects the government’s own understanding that the wider public wants surveillance to be objective, reasonable and proportionate.

Australians accept, I think, that the use of this technology to spot a terrorist plotting an attack is legitimate. Many would argue that the use of this same data by a local council, for example, to fine a dog owner should their pampered pooch perform a faux-pas on a public street is entirely unacceptable.

If facial-recognition technology were used to be used in this way, I believe the legitimacy of the system would begin to dramatically fade in the public’s eyes.

We need to guard against the line creeping towards broader social surveillance.

The Law Council believes reasonableness and proportionality should be managed within the legislation itself. We believe the government should also be highly conscious of how the law is seen to operate and, in particular, maintain robust levels of transparency and accountability. In its current form, the Bill is entirely unacceptable – a line drawn too far.

It is not only a question of where we draw the line between safety and privacy – it is also about how we ensure that line is vigorously maintained and defended.

Australians want to understand how their data is used and gathered. They want to be able to give informed consent when supplying information and know that the intended use of their information won’t be reappropriated.

We need to guard against the line creeping towards broader social surveillance. If the system was used to detect and fine jaywalkers, for example, then Australia itself is inching towards a full social credit-style system of government surveillance on the public.

The Law Council is seeking assurances – in legislation – that any line creep will not be able to occur without careful foresight of the consequences of that creep and an engaged public debate about why that creep is justified.

Furthermore, the stability of the line must be legislated for and not just left to the anticipated good intentions of future governments.

The onus must be on government and legislators to justify why they need further oversight of our lives.

Morry Bailes is the managing partner at Tindall Gask Bentley Lawyers, president of the Law Council of Australia and is a past president of the Law Society of SA. The opinions expressed in this column are his own.