Norwegian energy company Equinor has been ordered to modify and resubmit an environmental plan to drill an oil exploration well in the Great Australian Bight.

The company has exploration rights on a site about 370km off the South Australian coast and first submitted its environmental statement on the drilling proposal in April.

After previously delaying a decision, the National Offshore Petroleum Safety and Environmental Management Authority (Nopsema) on Monday again called on the company to provide more information on the consultation it conducted and on the risks posed by oil spills.

“The opportunity to modify and resubmit does not represent a refusal or rejection of the environment plan,” the regulator said.

“This is a normal part of Nopsema’s environment plan assessment process.”

Equinor has 21 days to respond and can ask for more time.

It said it remained committed to drilling the exploratory well and to meeting all its regulatory requirements.

“Based on the industry’s experience, we know Nopsema accepts only 10% of plans on first submission,” the company’s Australian manager, Jone Stangeland, said in a statement.

“Equinor has always expected to work through an iterative process of resubmission before Nopsema accepts the environment plan.

“We continue to engage with stakeholders and local communities regarding details of our plans.”

South Australian senator and Greens environment spokesperson Sarah Hanson-Young said the Norwegian oil giant should “quit while it still can”.

“There’s no safe way to drill in the Great Australian Bight, and South Australians, and Australians alike, will not give big oil a green light – not now, and not ever,” she said.

“The company’s environment and safety plan has been rejected, after failing to deal with the risk of an oil spill, amongst other flaws. The environmental and economic risks are too high and there is no support in the community for turning our Bight into an oil field.

“The ecological and environmental significance of the Bight is priceless. Thousands of fishing and tourism jobs rely on it. It must be protected, with World Heritage listing, not exploited for more dangerous fossil fuels, especially in this climate crisis.”

Greenpeace and other environmental groups echoed the sentiment that the company should simply abandon the proposal.

“This is the second time that Nopsema has asked Equinor to fill in the gaps in its drilling plan despite the company having more than two years and several attempts to get it right,” campaigner Nathaniel Pelle said.

“The communities of the Bight, traditional owners and the thousands of people in the seafood and tourism industries whose livelihoods depend on healthy oceans will never accept oil drilling in the Bight.

“Opposition today is greater than ever. Equinor’s senior management needs to accept this reality and abandon its reckless plans for good.”

If approved Equinor expects to begin drilling its Stromlo-1 exploration well in the summer of 2020/21.

In information released by Nopsema, the work is expected to take 60 days using a mobile offshore unit supported by three vessels and helicopters.

The well will not be cored or production tested for hydrocarbons and will be permanently plugged.

Equinor will then evaluate the results before considering whether to proceed with appraisal or further exploration.