The acting prime minister, Michael McCormack, defied a Senate order to produce documents relating to the government’s troubled regional grants program, despite early advice from the department suggesting information should be released.

The regional jobs and investment packages program was subject to a scathing federal audit released on Melbourne Cup day which found ministers knocked back almost 30% of recommended projects and supported 17% of those not recommended.

Labor has been attempting to access documents underpinning the government’s decision-making process, but the government has refused to comply with a Senate order to produce the information.

Email correspondence released under freedom of information laws also shows the minister’s office scrambled to find a reason not to provide the documents to the Senate.

According to an email sent from Donna Wieland, the general manager of regional programs in the Department of Infrastructure, Transport, Cities and Regional Development, the department proposed to “package up the requested information into two lots”.

“The first pack will be documents that are not particularly sensitive that can be released. We should be able to meet the deadline for those.



”The second pack will be documents that the minister may wish to consider ‘public immunity interest’ reasons for non-disclosure.”

Wieland tells the minister’s office that claiming “advice to government” is not a grounds to deny the information, but suggests that “damage to commercial interests and unreasonable invasion of privacy are”.

She warns that it will likely be a “complex task” to claim these grounds.

The correspondence, released following an FOI request by the Labor party, also shows that advice was provided to the department by the Department of Prime Minister and Cabinet, which stressed that the minister would need to identify the “specific harm of disclosure” of defying the request.

Wieland also canvasses the idea of claiming “cabinet deliberations” as a grounds for refusing the release of documents, saying it could be “further explored”.

However, despite initially suggesting one tranche of documents be released, following discussions between the infrastructure department, the minister’s office and the prime minister’s department, no documents were tabled.

Labor’s shadow infrastructure minister, Catherine King, accused McCormack of “treating the people of Australia with absolute contempt”.

“Senior officials in his department and own staff were originally comfortable releasing some documents but then worked with the prime minister’s department to not release a single page.”

King seized on correspondence suggesting that McCormack used a template letter supplied by the prime minister’s department to claim release of information was an “unreasonable invasion of privacy”.

“However, the program guidelines clearly state that confidential information relating to applications may be provided to parliament,” she said. “Michael McCormack must stop acting like the rules don’t apply to him and start being honest with the Australian people.”

According to the guidelines for the regional jobs and investment packages scheme, applicants were advised that information could be released to members of parliament or parliamentary committees.

McCormack has defended the regional grants program, saying ministers overruled departmental advice based on what was “best” for regional Australia.

On Tuesday, a spokeswoman for McCormack said the government had co-operated with the audit, “which did not find any evidence of electorate bias in application assessments by the ministerial panel or of any contravention of commonwealth grant rules and guidelines”.

“The Government determined that documents relating to the 13 November Senate order could, if publicly released, damage commercial interests and risk reputational damage to companies involved in open tender processes, while the potential release of private information submitted during program applications would create an unreasonable invasion of privacy.”