Agriculture Minister Barnaby Joyce's angry outburst against the government's approval of a massive Chinese-owned coal mine may have breached strict protocols for ministerial behaviour and cabinet solidarity.

The updated 2015 cabinet handbook says ministers must not "express private views on Government policies nor speak about or otherwise become involved in a ministerial colleague's portfolio without first consulting that colleague and possibly the Prime Minister".

Barnaby Joyce has ruled out resigning from cabinet over the decision to allow the open-cut mine. Credit:Sahlan Hayes

The handbook also lists protocols for cabinet solidarity. "Cabinet ministers cannot dissociate themselves from, or repudiate the decisions of their Cabinet colleagues unless they resign from the Cabinet," it says.

Mr Joyce this week greeted the approval of the mine in the heart of the fertile Liverpool Plains in his New England electorate with the memorable – and damaging – phrase "the world has gone mad".