Independent senator Jacqui Lambie's comparison of the Greens to Islamic military extremists has left the political group demanding an apology.
Addressing a mining conference in her home state of Tasmania on Friday, Senator Lambie opened her speech with "a little joke".
"What's the difference between the Greens and ISIS?" she asked an audience gathered for the third and final day of the Tasmanian Minerals and Energy Council annual conference.
"Not very much. They both want to take us back into the dark ages."
Pre-empting a backlash, Senator Lambie said she was not talking behind the Greens' backs.
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"I told the same comments (to) a group of Green senators at the last sitting of Parliament.
"I make no apologies. They need to be told, and often."
However, Tasmanian Greens leader Cassy O'Connor took offence.
"It is outrageous to compare Greens and conservationists with murderous terrorists," she told reporters.
"It's unnecessary, divisive language and she should apologise."
Senator Lambie's comments came in response to a United Nations committee decision in Germany on Thursday to uphold protection measures across Tasmania's 1.5 million hectare Wilderness World Heritage Area.
"The people from the UN would be better off listening to the average person from northwest Tasmania than the environmental zealots and alarmists like the Wilderness Society's Vica Bayley, who will never be satisfied until we're all living in caves, burning candles and eating tofu," she said.
The first-term senator renewed her call for an upper house inquiry into the activities of the Greens, citing the party's move to shut down Tasmania's mining and logging industries.
"The key question is: did they use taxpayer funds to kill off Tasmanian jobs and sabotage a sustainable, environmentally friendly industry?"
Senator Lambie went on to tell the conference that she struck a deal with federal Environment Minister Greg Hunt, that guaranteed Tasmania the right to burn wood waste to produce energy, in exchange for her support of the renewable energy target legislation.
"Let's see if he keeps his word," she said, according to News Corp.
