Government urged to expand mining tax The Gillard Government has been urged to expand its controversial mining tax to include copper, uranium and gold at a Senate inquiry into the tax this morning. Leading economist Dr Richard Denniss from the Australia Institute said mining taxes were an efficient and effective way for governments to raise money, but he said the mining tax imposed on Australia over the past nine months had been developed in a poor way. Dr Denniss said the exclusive focus of the tax on iron ore and coal miners was too narrow, and other commodities like gold, uranium and copper should have been included too. "We should simplify the tax by broadening it," he said. There is no reason to have excluded gold and we would be collecting a lot more revenue now if gold was included. When asked if all minerals should be included, Dr Denniss agreed. When challenged that many minerals were not currently making the super profits that iron ore and coal have in recent years, Dr Denniss said the tax could be structured in way that would allow poorly performing sectors to avoid paying anything. "On a conceptual level if you like it for one asset you like it for all assets," he said. The Labor Party has previously resisted calls from the Greens for further minerals to be included under the tax, and new Resources Minister Gary Gray has also ruled out tinkering with the tax. The mining tax was famously devised by Ms Gillard in partnership with three major mining companies - BHP Billiton, Rio Tinto and Xstrata - and Dr Denniss said a better outcome would have been achieved if more people, including the state governments, had been involved in the process. "If we had have had a more transparent process we would have had some more people putting ideas on the table," he said. The Senate inquiry is set to run all day in parliament house, and the schedule includes Treasury Secretary Dr Martin Parkinson and key figures from the Australian Tax Office.