Using freedom of information laws, the state opposition asked Mr O’Brien’s Department of Primary Industries for all modelling and briefings behind the press release.

The case will cast more doubt on Mr Baillieu’s commitment to genuinely reform the state’s freedom of information laws – a key election promise.

In 2010, Mr Baillieu attacked the Brumby government for its attitude to freedom of information, which had ”made it extremely difficult to obtain a clear and truthful understanding of the government’s activities”.