German MPs on Thursday rejected a call to clamp down on road-blocking climate activists with prison sentences of up to five years.
Protesters from a group called the Last Generation meanwhile vowed that “only effective climate action will make us stop”.
The group's tactics, which include gluing themselves to roads and vandalising artwork, have stirred anger and debate in Germany.
Similar stunts by groups such as Just Stop Oil and Extinction Rebellion have taken place in Britain.
Guenther Krings, a conservative German MP, said protesters were behaving “arrogantly and cynically” as he backed his party's call for minimum prison sentences.
The main centre-right opposition called for prison terms of between three months and five years for protesters causing disruption and damaging artwork.
Most activists found guilty in court have been fined or handed short prison sentences by German judges.
Mr Krings warned of a “spiral of escalation” and direct action from “very different political angles” if the protests are tolerated.
“Freedom of protest is not a licence to exploit thousands of citizens for the sake of your own radical positions,” he told the parliament.
“This debate is not about climate change at all but about freedom of movement, the protection of property and cultural goods, and the defence of the rule of law.”
MPs from Chancellor Olaf Scholz's centre-left coalition said they did not approve of the protest tactics but said the current criminal law was sufficient.
This week, police launched 270 criminal investigations following protest incidents in Berlin, said Social Democratic MP Sonja Eichwede.
“What the Last Generation is doing cannot be tolerated — and it isn’t,” she said.
Liberal MP Stephan Thomae said the protests “overstep the mark” and only aided the “self-promotion of people with an exaggerated sense of mission”.
But “as little as the gluing helps the climate, these harsher punishments would help us equally little against the gluers”, he said.
A motion rejecting the call for tougher punishments was passed by a show of hands.
Mr Scholz has said he has little time for the activists.
The Last Generation on Thursday staged a fresh protest blocking traffic on major Berlin roads.
The group said its demonstrations would continue on Friday despite anger from politicians.
“We will continue our peaceful resistance as long as the climate catastrophe pushes on the destruction of our civilisation,” said group spokeswoman Carla Rochel.
