Labor and the Greens are pressing Prime Minister Malcolm Turnbull to explain what was said in a meeting that led to a $443.8 Million grant awarded to a small not-for-profit group for the Great Barrier Reef without a tender process.

"If he won't come clean, I am going to ask the committee to support my suggestion as chair of this inquiry to call the prime minister and the environment minister to answer questions at the next hearing," said Greens senator Peter Whish-Wilson, who is chairman of a Senate inquiry examining the process behind the grant.  "If the prime minister and environment minister ignore that request, then there are other options the Senate can pursue to get them to answer questions."  He adds that he never heard of any prime minister awarding such a chunk of money to a little-known group.

In April, Mr. Turnbull had a meeting with environment and energy minister Josh Frydenberg, and the Great Barrier Reef Foundation chairman John Schubert.  Environment and energy department secretary Finn Pratt, was not present.

"It seems there was no public servant in the room.  That worries me," said Labor Senator Kristina Keneally.  "First of all, it could mean that there is no official record of the meeting.  Secondly, it suggests Malcolm Turnbull went into that meeting without proper advice."

She continued, "What advice did Malcolm Turnbull receive from Treasury about the financial risks of giving away $444 Million of public funds in one go to a small, private foundation?  What did the Department of the Environment tell him about the risks of handing responsibility for the reef's future to one tiny private charity?  Or did he have any advice at all?"

The Prime Minister's office hadn't commented on these events at the time of this story's publication.