A Tiwi traditional owner has lost a late Federal Court bid to prevent Santos building an underwater gas pipeline near the Top End islands.
Simon Munkara, a member of the Jikilaruwu clan, filed proceedings on Monday and applied for an urgent injunction to prevent Santos commencing pipeline work while the case is heard.
Judge Natalie Charlesworth rejected the application but will hear further arguments on Wednesday.
She said Tuesday night's emergency bid was filed too late for Santos to make submissions.
"I just cannot see how I can afford Santos procedural fairness which is my obligation," she said during the hour-long hearing.
"Early work on the pipeline - that is of the next few days, will not impinge on the interests of (Mr Munkara)."
In the 20 hours between Tuesday's decision and the next court sitting, Santos will be permitted to start work laying the pipe as long as it's not in the "area of concern" for traditional owners.
Santos' lawyer John Waters SC said a ship is sitting off the port of Darwin ready to commence work on Wednesday morning.
"The vessel has been procured, it's a costly exercise ... and my current position is that it should not be interrupted," Mr Waters said in the hearing.
Mr Waters said the pipe laying works at a speed of three kms per day and it would take over 10 days to reach the area of cultural concern.
By that time, Justice Charlesworth will have made a decision on whether to block Santos from further work.
Mr Munkara argues Santos has not properly assessed submerged cultural heritage along the route of its Barossa export pipeline, which runs within 7km of Bathurst Island.
He says the approval Santos is relying on is of an environment plan accepted by offshore regulator NOPSEMA in March 2020, without a proper assessment of the risks to underwater cultural heritage.
Last week, six Jikilaruwu senior elders made an application to Environment Minister Tanya Plibersek to protect their underwater cultural heritage under the Aboriginal and Torres Strait Islander Heritage Protection Act.
In response, Santos sent a statement to AAP saying an independent expert had found "there are no specific Indigenous underwater cultural heritage places along the Barossa pipeline route to which people may have spiritual and cultural connections that could be affected by Barossa pipelaying activities".
Tiwi traditional owners have commissioned reports from different independent experts who found that, if installed in the current proposed location, the pipeline would damage sea country, dreaming tracks, Songlines and areas of cultural significance.
Mr Munkara is asking the court for an injunction to prevent pipeline activities proceeding until Santos has submitted a revised environment plan and NOPSEMA has made a decision.
"We are going to court because we can't let Santos build a pipeline through our songlines and our ancestors' burial grounds," he said.
"Santos doesn't want to hear this story, so we are going to court.
"My country, both the land and sea, it's everything to me and my kids, the sea is part of us."
Greens Senator Dorinda Cox said the report Santos is relying on has been dismissed by the Tiwi Land Council and that she was "outraged".
"TLC's chief executive officer Robert Graham is also an anthropologist and understands the local people and cultural heritage and I agree with his reported assertion that Santos' assessment is a continuation of a failure to consult traditional owners properly," she said.
"The area contains ancient burial grounds, traditional songlines and totem animals."
