Lawyers have sounded the alarm bells over an agreement allowing children as young as 10 to be held without charge for up to two weeks on suspicion of terrorism offences.
The Turnbull government and the states and territories agreed to the new pre-charge detention regime at a meeting in Canberra this week at which Victorian Premier Daniel Andrews derided civil liberties concerns as a "luxury".
But Fiona McLeod, president of the Law Council of Australia, said such concerns should not be so lightly dismissed, and condemned the decision to lock up children without charge as "draconian".
"It's the combined shock of having a combination of a pre-charge detention of up to 14 days and the revelation they're going to seek to have this extended to the age of 10," Ms McLeod told Fairfax Media.
"We're talking about draconian steps there and we believe that's crossed the line of intruding on civil liberties too much."
The federal Labor opposition also hit out at the agreement. "It's a shocking and drastic step to propose, without charge, the detention of a child of 10 years old," shadow attorney-general Mark Dreyfus??? said.
Justice Minister Michael Keenan on Saturday made the case for extending the regime to include 10-year-olds, arguing it was regrettable but necessary because Islamic State deliberately recruited children.
He noted that 10 was also the age of criminal responsibility under criminal law and that safeguards allowed minors to have parents and lawyers present when questioned.
"The reason we're doing this - and it's a most unwelcome reason and no one in the government is happy about this - but unfortunately ISIL specialises in targeting children," Mr Keenan told Channel Seven's Sunrise program.
"And we've had bitter experience in Australia because it was a 15-year-old just out here in Parramatta that murdered Curtis Cheng, the employee of the NSW Police."
Ms McLeod was unswayed by that argument and said police already had the powers to detain minors and interview them if they believed a crime was imminent.
"There are sufficient powers there. We haven't had demonstrated to us what the gap in the current criminal justice response is," she said.
"Any teacher, any criminologist, any psychologist would tell you that children's brains are maturing right through their teens and that you need to treat children differently."
Under the agreement with state and territory leaders, the Commonwealth will make it a federal offence to possess "instructional terrorist material" or to conduct a hoax terrorist act.
Mr Andrews, the Victorian Labor premier, was the most enthusiastic about the new regime and hit out at civil libertarians by deriding their concerns as a "luxury".
"There will be some today who will focus on the notional infringement, the notional reduction in people's rights and liberties and freedoms, the rights and liberties of a small number of people," he said.
"Some people have the luxury of being able to have that notional debate. Those of us in positions of leadership do not have that luxury.
"We are called to act and we are called to make the changes necessary to give to law enforcement and our security agencies, everything they need to keep Australia safe - and that is what this COAG meeting today has done."