The Green Party in Australia says it is ecologically irresponsible of the federal government to allow the company at the centre of an offshore oil spill to extract more oil.
The Greens have been highly critical of the government's handling of the oil spill, which has been leaking for more than two months into the Timor Sea.
Three attempts to plug the oil well have been unsuccessful.
Green Party leader Bob Brown criticised the government for awarding Thai-based company PTTEP Australasia a "massive new area for oil exploration in Australian waters."
Senator Brown told the Nine Network on Sunday that it was ecologically irresponsible to reward the company's failure with further exploration leases.
The Greens believe anywhere from 10 to 20 million litres of oil has spilled into the ocean since the leak began on 21 August.