The state government has been accused of a "disgraceful" attempt to sneak approval for new buildings on public land at Moore Park through Parliament in a package of unrelated legislation.

In a bill that deals largely with minor changes to earlier legislation, the government has proposed an amendment to the Sydney Cricket and Sports Ground Trust Act to give the trust the ability to draw up long-term leases with the Australian Rugby Union and the University of Technology.

These leases would allow the construction of new multi-storey buildings on land currently used as a car park for SCG members, according to Sydney MP, Alex Greenwich, who has been briefed on the plans.

Mr Greenwich slammed the attempt to legislate for what could be a controversial privatisation of public land through an unrelated bill. He said he had been briefed by the office of the Sports Minister, Stuart Ayres, that the idea was to construct a five- to six-storey building on what was currently the SCG Members gold car park.