Immigration Minister Peter Dutton has put forward amendments to the 2015 Australian Border Force Act that will effectively strip out rules that threatened detention centre workers – including teachers, lawyers and social workers – with two years in prison if they spoke out about neglect or abuse.

The government has long argued the Act did not prevent people disclosing information that was in the public interest, and Mr Dutton says his amendments merely aim to "clarify" the reach of the controversial provisions.

But Barri Phatarford from Doctors for Refugees – which helped bring a High Court challenge against the laws that originally also covered doctors and nurses – said the government had completely capitulated.

"Short of repealing the law completely this in practicality waters it down so much that it's virtually non-existent," Dr Phatarford told Fairfax Media.

"Mr Dutton has had two years to clarify this draconian law but he hasn't. He's clarifying it now because the government is in the middle of a High Court challenge which frankly they know they cannot win."

Doctors for Refugees and the Fitzroy Legal Centre brought the constitutional challenge against the laws last year on the grounds they breached doctor's implied constitutional freedom of political communication.

The government subsequently exempted health professionals from the laws but the groups refused to drop the case, arguing doctors could not properly treat detainees if non-health professionals – such as teachers, cleaners and cooks – could not report or share information without fear of prosecution.

The provisions will now only apply to information that could compromise Australia's security, defence or international relations, interfere with the investigation of offences, or go to sensitive personal and commercial matters.

Mr Dutton says the amendments aim to clarify the laws so that they "reflect the original policy intent" – to prevent the unauthorised disclosure of information that could cause harm to the national or public interest.

Sensitive information will remain closely protected but "without unnecessarily restricting informed public debate", Mr Dutton said.

"There must be a balance between the competing interests of transparent, open and accountable government with the necessity of protecting certain information from disclosure which would lead to identifiable harm," he said.

Mr Dutton said the original provisions were adapted from the model in place for the former Australian Customs and Border Protection Service but "this model has not kept pace with the developments in the modern border environment".

Once passed through Parliament the changes will be applied retrospectively, meaning people who made disclosures over the past two years that could have been considered an offence under the original rules cannot be prosecuted.

Managing solicitor at the Fitzroy Legal Service, Meghan Fitzgerald, called it "an astounding turnaround" and a clear attempt to avoid the scrutiny that would have come if the case proceeded in the High Court.

"In the time these laws have been in place, workers in immigration detention centres, including doctors, nurses, teachers, counsellors, security guards, lawyers and registered migration agents have lived in fear of speaking out about the shocking conditions refugees and asylum seekers are suffering," she said.

In the past, Mr Dutton has said that describing the provisions as a gag was "factually incorrect and highly misleading". The laws did "not restrict anyone's ability to raise genuine concerns about conditions in detention should they wish to do so through appropriate channels," he said.