The asylum seekers have been detained on the high seas, outside of Australia's migration zone, since their boat was intercepted on its way from India on July 7.
Stephen Donaghue QC, representing the government, says the Commonwealth has no plans to send the asylum seekers to Sri Lanka.
Dr Donaghue told the High Court in Melbourne on Friday the government would stick to its undertaking that no one on the boat would be sent to another country without three days written notice.
Justice Kenneth Hayne said given the asylum seekers were in custody it was important the legal battle over their future was finished as quickly as possible.
"The parties are just going to have to bend their back to get on with it," he said.
"I am not going to let this case devolve into a procedural morass. There's got to be some sense shown."
Justice Hayne said the case appeared to come down to whether the Australian government had the power to intercept the asylum-seekers and take them to a country other than Australia.
He adjourned the case until Friday afternoon.
