Mining spokesman Jeremy Buckingham questioned why the government was repeatedly blocking access to documents after the Greens moved a “call for papers” on the project six times. Each time the government has blocked the motion.

The Shenhua Watermark project is currently before the Department of Planning after public submissions closed.

“Why is the National Party covering the tracks of Ian Macdonald on an exploration licence that most people think should never have been granted in such a productive agricultural area,” Buckingham said.

“Given the serious probity issues relating to other coal licenses granted by Ian Macdonald, it is only reasonable that parliamentarians should want to look into circumstances of the coal grants over the Liverpool Plains.

“The government's constant rejection of this call for papers indicates that they are more concerned with supporting the Shenhua Watermark coal mine than in transparency and probity of the operation of the Mining Act.”

If the government continues to block access, the Greens will try to move the motion by contingency and therefore force a public debate on whether the documents should be made public, according to Buckingham.

“The Shenhua Watermark licence should never have been granted as it threatens the productivity of some of the most fertile cropping country in Australia," he said.