Lawyers for refugees have argued a high court ruling relating to dozens of medical transfers of refugees could deny their access to justice.
The High Court has granted the Federal Government the right to appeal a decision by the Federal Court to allow their cases to be heard before the jurisdiction.
The government's legal action was in response to more than 50 individual cases brought on behalf of refugees and asylum seekers offshore.
Lawyers had filed the cases with the Federal Court under the common law of negligence in an attempt to expedite their medical transfer from Papua New Guinea and Nauru.
National Justice Project senior solicitor Anna Talbot. Source: SBS News
National Justice Project senior solicitor Anna Talbot told SBS News the appeal process risked making it harder for their cases to be heard.
"We were bombarded with very sick clients who are in Nauru - most of them being very young children - young teenagers," she said.
"We were forced to seek court interjection so the minister would do what he needed to do and get the children help."
If the appeal is successful - it will mean the High Court is the only jurisdiction, which could hear the cases.
The suit centres on four test cases represented by the National Justice Project and Maurice Blackburn lawyers.
The Federal Government argues the Federal Court has no jurisdiction to hear the cases brought on behalf of those in offshore detention.
Lawyers for refugees have attempted to expedite medical transfers by forcing injunctions for patients to be transferred from Papua New Guinea and Nauru.
The strategy was used before the introduction of the so-called medevac legislation, which has since been repealed by the Federal Government.
The Australian government argues current medical transfer provisions are adequate to service the needs of refugees and asylum seekers offshore.
Ms Talbot said cases taken on behalf of refugees and asylum seekers would fulfil a duty of care to those in offshore detention.
“A lot of those people that were brought over in those initial federal court applications are still incredibly sick,” she said.
“It's not as legally simple to be running cases in the high court because of the rules of what they will and won't decide.”
Lawyers against the decision are concerned the High Court is a more expensive and difficult authority in which to lodge a case.
The appeal could also have implications for future compensation claims seeking damages over negligence and access to medical treatment.