Liberal Senator Richard Colbeck says Mr Burke has failed to set terms of reference for the inquiry which he announced more than two months ago.

On December 2 last year, Mr Burke told the National Press Club he was going to get tough on overpaid and poorly governed rural R&D corporations.

Mr Burke said he would ask the Productivity Commission to conduct "a review into the governance, efficiency, and duplication issues surrounding the research and development corporations. The precise terms of reference of that review and the timing will be announced in the near future."

The Productivity Commission told Budget Estimates today that it has not "yet received the terms of reference from the Government".

Senator Colbeck said Mr Burke was dragging the chain in a number of areas awaiting decisions.

"If anything, there needs to be an inquiry into the governance and efficiency of the Office of the Minister for Agriculture, Fisheries and Forestry," Senator Colbeck said.

"Whether it be in making a decision on extending drought assistance to farmers, finalising changes to the Horticulture Code of Conduct or releasing the Government's new Recreational Fishing Policy or many other long-waited decisions, Minister Burke is simply up to his neck in work needed to be done.

"Minister Burke must release the terms of reference immediately and provide them to the Productivity Commission so they can get on with their work."