Labor, One Nation and Rex Patrick unite to decry Coalition?s refusal to release national cabinet documents

It's rare to see an issue unite the federal Labor leader, Anthony Albanese, independent senator Rex Patrick and One Nation's Malcolm Roberts with such passion.

But all three in the past week have launched extraordinary attacks on the prime minister's department for insisting that national cabinet documents remain secret under FOI laws, despite the government losing a case brought by Patrick in the Administrative Appeals Tribunal on that very point in relation to a previous FOI application.

On Tuesday, Patrick escalated the dispute in the Senate, labelling the department's secretary, Phil Gaetjens, a "disgrace", a "henchman" for Morrison, and a "cover-up expert" over what he alleges is the department's improper use of the cabinet documents exemption.

Patrick also used the Senate to name two officials from the department - Angie McKenzie and Hugh Cameron - as rejecting his freedom of information requests for national cabinet documents on the basis of the disputed exemption, which he argued amounted to bureaucrats ignoring justice Richard White's decision in the Administrative Appeals Tribunal.

The Morrison government insists national cabinet is a subcommittee of the federal cabinet, despite justice White finding in the AAT in August that the evidence before him in a dispute over a previous application by Patrick did not support that view. McKenzie's decision, from which Patrick read in the Senate last week, explained that she had determined national cabinet to be a subcommittee on the basis of additional evidence not necessarily before the AAT in the prior case.

White cited factors including that national cabinet members "did not regard themselves as bound to support decisions" made there. The department did not appeal against the decision.

In response to the decision, the Coalition introduced but failed to pass a bill to expressly exempt national cabinet documents from FOI but is now routinely blocking FOI requests on the basis of cabinet confidentiality.

In September, the national cabinet reasserted that disclosure of its documents and deliberations would "undermine the trust between the commonwealth and the states and territories and would prevent full and frank discussions that achieve the best outcomes for the Australian public".

At Senate estimates, departmental officials explained they were not bound to apply White's findings to other FOI cases.

Deputy secretary of governance, Stephanie Foster, said White was "making decisions on a particular case, on the basis of the facts in front of him in that case".

First assistant secretary of the government division, John Reid, said the decision "has no precedential force beyond the facts before it".

"The department is absolutely not ignoring the decision of justice White," he said. "The decision of justice White has been drawn to the attention of all decision-makers."

The stance has irritated not just Labor and Patrick but also One Nation's Roberts, who told the Senate on 23 November that it was "fallacious" to claim national cabinet documents were cabinet-in-confidence because national cabinet was a "fabrication" and "a pretend concept".

"The name sounds grand, yet it's nothing more than a meeting of the prime minister and state and territory premiers and chief ministers," Roberts said.

Albanese, who has also attempted to get national cabinet documents under FOI, told Guardian Australia the department's decision to reject his request was "extraordinary", warning that the prime minister's department was "not above the law".

"Mr Morrison's obsession with secrecy has undermined the law that protects all Australians' right to know and, if left unchecked, threatens other fundamental rights," he said.

Patrick has been pursuing the issue in the Senate for months, including seeking answers on how much the department is spending defending "untenable" FOI decisions.

Patrick has also asked the Office of the Australian information commissioner to send one of the rejections to the federal court for determination.

Last week, and again on Tuesday, Patrick in the Senate accused McKenzie, one of the decision-makers who refused one of his requests, of being a bureaucrat who thought it was "in their remit to overturn a judicial officer in favour of the opinion and interests of her political master".

On 26 November, Gaetjens and the Australian public service commissioner, Peter Woolcott, wrote to the Senate president complaining that Patrick had made "derogatory comments" about McKenzie.

They said Patrick had "misused" parliamentary privilege to make comments accusing McKenzie of politicised decisions which if they "had been made in most other workplaces they could be characterised as bullying and harassment".

"McKenzie is a highly regarded and competent, professional public servant and conducts herself with the highest standards of integrity," they said.

"As Ms McKenzie's employer, we strongly object to senator Patrick's unwarranted and offensive remarks and ask that senator Patrick be directed to withdraw these comments."

On Tuesday, Patrick accused another decision maker in the department, Cameron, of using "what was effectively a pro forma decision-making template" to claim cabinet confidentiality over national cabinet documents to which he had sought access.

"Some might think it is unconventional that I come into the chamber and start naming public officials - but there are conventions being broken inside of government that are far more harmful," he said.

Patrick said that Gaetjens "hasn't lead the public service in a highly professional way" and "has been happy to act as the prime minister's henchman, covering up all manner of sins and corruption in the government".

The government leader in the Senate, Simon Birmingham, said Patrick's comments were an "extraordinary display" and a "politicised attack" against public servants.

Birmingham said parliamentarians ought to respect that public servants were not elected or public officials and should not single them out and impugn their motives.

"It was entirely appropriate for the secretary [Gaetjens] to seek to defend public servants from being brought into improper political debate."

The prime minister's department in a statement said: "PM&C wholly rejects senator Patrick's latest allegations. These continued personal attacks on APS staff remain unwarranted and untrue."

Guardian Australia approached Gaetjens, McKenzie and Cameron for comment.