Four days later the Labor member for Macquarie Fields, Andrew McDonald, publicly called on the State Government for an independent inquiry into the school and the proposed sale of adjoining farmland.

The Sydney Morning Herald has obtained an email from the office of the Education Minister, Verity Firth, written on February 13, discussing the possible terms of a Hurlstone inquiry.

It said the inquiry material had not been seen by anyone outside the minister's office, including Dr McDonald.

The next day Ms Firth's ministerial adviser, David Boyd, wrote an email to Dr McDonald saying: "At the Premier's office's request, the Education Department whipped up a first draft of what the inquiry could look like. It needs a fair bit of refining and your feedback will be essential for getting it right … the terms of reference in the attached have been endorsed in general terms by [the Premier's chief of staff, Graham] Wedderburn, so you're safe to call for any of those things."

In his reply, Dr McDonald said the inquiry needed to be broader.

He also said he was "very worried electorally about the issue".

The Opposition education spokesman, Adrian Piccoli, said yesterday the documents indicated the Hurlstone inquiry was a "stunt cooked up in the minister's office in order to make the local member look good".

"Four days before he called for the inquiry, Andrew McDonald didn't know anything about it," he said.

"It is becoming more and more apparent that the Hurlstone inquiry is a sham and the sale of the school land is a foregone conclusion."

Dr McDonald said the idea for an independent inquiry was his and that he had floated it with the Premier, Nathan Rees, and Ms Firth as early as late last year.

"When you are going to announce you want a government inquiry, of course you let them have a heads up," he said.

"While I did let my bosses know, it is not the same as asking for their permission.

"The call for an independent, wide-ranging and open-minded inquiry was my idea."

Mr Boyd told the Herald yesterday Dr McDonald had privately advised the minister's office of his intention to call for a Hurlstone inquiry as early as last December.

It was normal practice for backbenchers to give warning of any public announcements to ministers concerned, he said.

"The inquiry was definitely Andrew McDonald's idea," Mr Boyd said.