The Turnbull government’s controversial $443.8 million funding grant to the Great Barrier Reef Foundation contains secrecy provisions more onerous than cabinet papers, Labor has alleged.

Shadow environment minister Tony Burke said on Sunday the 98-page grant agreement rivalled “the ozone layer” for holes.

“Under the agreement they’ve signed, it is completely lawful, completely OK for the foundation to wine and dine the mining and banking executives who are on their chairman’s panel, up and down the Queensland coast, in the name of trying to win them over for more fundraising,” Mr Burke told the ABC.

“Not only is it allowed, we might never know if it’s happened because that exact clause is covered by the confidentiality provisions and these are confidentiality provisions that are more strict than cabinet papers.

“Cabinet papers are confidential for 20 to 30 years. The confidentiality clauses over their fundraising activities can go in perpetuity, forever.”

Mr Burke said the grant amounted to “effectively the privatisation of a large chunk of the public service”.

He also alleged the charity’s Chairman’s Panel was full of “a whole lot of the corporate mates of the Prime Minister”. He did not elaborate.

The panel’s more than 50 members include titans of industry at such well-known firms as JP Morgan, Commonwealth Bank, National Australia Bank, Macquarie, BHP, Rio Tinto and Shell, as well as scientists and academics.

The large grant made headlines when it was announced in the federal budget in May. Newly-elected Labor senator Kristina Keneally has since thrust it back onto the national agenda through a Senate inquiry.

Much of the criticism has centred on the fact that the large grant was awarded without a competitive tender process, was not requested by the charity, and was awarded when the charity employed just 11 staff.

The charity’s CEO, Anna Marsden, has described receiving the grant as “like we’ve just won lotto”.

After questioning at the inquiry, the foundation revealed it was founded by the late Sir Sydney Schubert, a prominent public servant and founding director of the Great Barrier Reef Marine Park Authority; the late Sir Ian McFarlane, a shale oil developer; and John B Reid and David Windsor.

When pressed by the ABC’s Barrie Cassidy, Mr Burke declined to allege any illegality in the grant process.

Mr Burke also confirmed that, as minister, he had given the charity a funding grant for a research project. He denied any comparison between that grant and the government’s $443.8 million.

“[We] gave them money for a specific research project that they came to us wanting to conduct,” Mr Burke said.

“It was assessed by the department and it was determined it was an appropriate research project and we funded it.

“Here, no one knows what exactly they’re going to do. The foundation doesn’t yet know what it’s going to do with the money. All that they know for sure is that they’ve been given it.”

Environment and energy minister Josh Frydenberg has dismissed Labor’s criticisms as a “distraction”.

“There is a lot of transparency. There is a public agreement. As I said, the Audit Office will continue to be able to follow the money. You’ve got compliance with the governance guidelines. It’s an organisation which the Labor party contributed to, and it has some of Australia’s leading scientists and those who are involved in philanthropic organisations, so it’s a very reputable partner for the commonwealth,” Mr Frydenberg told the ABC last week.

“This is the largest single investment via government in reef preservation and conservation and the only reason the Labor party is raising this is because they abandoned the reef when they were in office.”