Protesters of Equinor's Great Australian Bight oil drilling exploration program have criticised the decision by the National Offshore Petroleum Safety and Environmental Management Authority's (NOPSEMA) to approve the company's environment plan.
The decision was made in late December, with NOPSEMA accepting the plan for its proposed Stromlo-1 exploration well, located 400 kilometres south west of Ceduna.
NOPSEMA imposed conditions on Equinor to ensure environmental protection, however this is the second of four approvals required before activity in the Bight can begin.
Equinor hopes to begin its operation later this year.
Penong's Catrina Spitzkowsky, who has long protested against drilling activity in the Bight, was "saddened and appalled" by the decision.
"NOPSEMA's decision is totally irresponsible on their part," she said.
"With bushfires happening around, we are only going to contribute to climate change by opening another oil field - this was the perfect time for the government to say we can't do it.
"People I've spoken to can't believe it is going ahead and they were saddened by the news."
She said local protesters would not be giving up their fight in the hope of putting a stop to the program.
"We are not giving up, we will be there every step of the way."
Streaky Bay's Heath Joske has also protested the Equinor project and said he was disappointed with the decision.
"I never had a huge amount of faith in NOPSEMA, seeing as the majority of members are ex-heads of oil companies or lobby groups," he said.
"The environmental risks and risks for fisheries and livelihoods are so great in this project, I just couldn't see how it could have been approved.
"A lot of people are devastated, it felt like all efforts seen here and across the country were not listened to."
Mr Joske said they would also continue the fight.
"It's not the end of the road, we will keep fighting, we are 100 per cent committed to the cause and if anything things will step up."
Equinor plans to use Ceduna as a base of operations for its project and Ceduna District Council mayor Perry Will said they would accept NOPSEMA's decision.
"We can't have any influence on it, NOPSEMA is an independent regulator and nobody can interfere with the panel," he said.
"It won't matter how much people jump up and down, that won't have any influence.
"It is a whole process and NOPSEMA have looked at Equinor's plan."
Mr Will said Equinor had not been in touch with the council since the decision was made, but should Equinor get complete approval for its program then the council would see what the next step might be.
The Elliston District Council was one of a number across the state to oppose oil exploration in the Great Australian Bight, and chief executive officer Geoff Sheridan said the council had not met since the decision was made to further discuss the matter.