Peter Dutton has pointedly backed the besieged Nationals deputy leader Bridget McKenzie ahead of the prime minister receiving formal advice about whether there has been a breach of ministerial standards in the sports grants controversy.

While the treasurer, Josh Frydenberg, was noticeably more circumspect about his thoughts on McKenzie’s future in a separate interview on the ABC on Sunday, the home affairs minister, who made a run for the prime ministership against Scott Morrison last year, told Sky News while he wasn’t in possession of all the facts, he knew McKenzie was a good minister.

“I know Bridget McKenzie as a good minister and somebody who has a lot of passion, frankly, in her current portfolio and when she was sports minister,” Dutton said.

While acknowledging processes were under way to determine key facts, Dutton declared the government should not “take a line from Twitter” in determining McKenzie’s future. “For me, I’ve got confidence in Bridget and I’ve been very clear about that from day one.”

With expectations firming that McKenzie will depart her post, possibly later on Sunday, the former Nationals leader, Barnaby Joyce, also took to social media over the weekend to mount a public show of support. “Until someone can tell me the law she broke or the money she personally misappropriated, I am going to back Bridget,” he said.

Joyce also shrugged off damning findings from the Australian National Audit Office about breaches of process, as well as the possibility that grants in the program were made without proper legal authority. He declared politicians should be in command, not bureaucrats.

“The fever of dissent is used for tactical political advantage by some and by the bureaucracy to deter any minister in the future of doing anything away from what they are advised to do,” Joyce said. “This divests the parliament of its proper powers.”

Morrison is expected to receive advice imminently from his departmental head and former chief of staff, Phil Gaetjens, who has been examining whether there has been a breach of ministerial standards. The prime minister will want the imbroglio resolved before the new parliamentary session opens this week.

Frydenberg would not say on Sunday morning whether McKenzie should stay or go. He also declined to say who should replace McKenzie as the deputy Nationals leader in the event she steps aside, arguing venturing an opinion would be like asking “a rabbi to be in the conclave choosing the pope”.

There is deep irritation in Nationals ranks that media reports last week have pointed to a deal to replace McKenzie with the Queensland frontbencher David Littleproud before the issue has been properly considered by the Nationals party room.

Both the Liberal and National parties become irritated when there is seen to be interference in their internal processes. Some Nationals predict if McKenzie goes, the deputy leadership would be contested rather than handed to Littleproud in a deal.

The treasurer was pressed repeatedly on Sunday to admit that the behaviour evidenced through the management of the sports grants scheme was blatant pork barrelling. Frydenberg declined to make that admission.

He said as a consequence of this case study, the government had already resolved to change the way sports grants programs were administered. “You will see more accountability, more transparency, more explanation of reasons, and they will be documented.”

“What it will mean for the government going forward is that when you have a corporate commonwealth entity like Sports Australia and the decision maker is the minister, the reasons will have to be documented for decisions, and that includes reasons for approving projects that weren’t recommended.”

It is unclear how Frydenberg’s comments sit with analysis from the ANAO that the minister lacked legal authority to make the grants, or with observations from constitutional law experts including academic Anne Twomey that the community sport infrastructure grant program was unconstitutional.

The attorney general, Christian Porter, has been examining the legal questions flagged by the ANAO, but not the question of constitutionality.

Frydenberg said the government would not look to fund programs that had missed out because the government skewed grants towards targeted seats, but instead look at funding a new program in this year’s budget.

“What the prime minister has foreshadowed is given the strong community need and the importance of supporting these sporting organisations, we would, in the context of the budget, revisit a program of this type,” the treasurer said.