Queensland Law Society president Bill Potts says Peter Dutton's call for mandatory or minimum sentencing of law-breaking protesters is extreme.
Home Affairs Minister Peter Dutton has been criticised for calling for mandatory sentences for people who break the law while protesting, and for suggesting protesters on welfare should have their payments cancelled.
Mr Dutton has taken aim at magistrates who impose "slap on the wrist" penalties on protesters after the Brisbane CBD endured a spate of recent traffic-stopping demonstrations.
"There needs to be mandatory or minimum sentences imposed," Mr Dutton told 2GB.
"A community expectation is that these people are heavily fined or jailed."
Ten people involved with environmental group Extinction Rebellion have been charged this week for blocking roads during morning peak hour.
It has followed months of regular protest actions in Brisbane and elsewhere in the state attended by thousands of people, mostly over environmental issues such as climate change and Adani's central Queensland coal mine.
But using mandatory sentencing to crack down on protesters would be extreme and populist, Queensland Law Society president Bill Potts said.
"Mandatory sentencing, more often than not, straight-jackets the courts," Mr Potts said.
"There is a complete difference between occupying an intersection for 10 minutes opposed to chaining yourself to a 44-gallon drum full of concrete and holding up a coal train for five hours."
Mr Dutton also said he agreed with suggestions from 2GB broadcaster Ray Hadley on Thursday that protesters go "ask Mummy and Daddy for cash" following reports some demonstrators received welfare.
"You're sitting on your backsides and you won't be getting paid (by) us," Mr Hadley said.
Mr Dutton's response was "I agree".
The Greens have seized on the suggestion, slamming it as undemocratic and "entirely inappropriate", with Greens leader Richard Di Natale telling ABC there were already laws in place to deal with protesters.
“Peter Dutton doesn’t know what living in a democracy means,” he said.
“One of the most fundamental rights in any democracy is the right to speak up and to protest against those in power … It’s starting to sound more like a dictator than he is an elected politician. Because somebody says something that he doesn’t like, that he doesn’t support, he’s saying we’re going to strip away income support.”