The South Australian parliament's upper house has been urged to give proper scrutiny to proposed new laws to ramp up fines for disruptive protests.
The new measures were rushed through SA's lower house last week with both the Labor government and the Liberal opposition supporting the changes.
They will go before the Legislative Council next week and could be approved as early as Tuesday.
But there's been growing opposition to the changes, which increase maximum fines from $750 to $50,000 along with potential jail time.
They were prompted by three days of action by members of Extinction Rebellion last week, including a woman who abseiled over a city bridge, forcing a main road to be closed for about 90 minutes.
A number of groups planned to march through Adelaide on Friday night to urge the upper house to look closely and potentially reject the legislation.
Amnesty International spokeswoman Adelaide Xerri said the bill's broad scope was concerning.
"This crackdown on the right to protest means all our ability to fight for human rights and combat the climate crisis are under threat," she said.
"People must not face huge fines, and even prison sentences, just for standing up for what's right."
Unions have also condemned the increased penalties along with Greens MPs in the upper house.
On Friday, the Law Society of South Australia posed a series of questions and said it was "deeply troubling" that those in favour of the higher fines had not explained the rationale for the changes or the urgency for their introduction.
The organisation also questioned why there was no public consultation.
Treasurer Stephen Mullighan said South Australians had always enjoyed the right to protest and could do it in compliance with the law.
But he said the majority of the community expected the parliament to act swiftly and severely in increasing the penalties.
"I hope that we've managed to send a clear message to those reckless, selfish people who put South Australian lives at risk," he said.
