Senator BIRMINGHAM (South Australia) (14:33): Mr President, I ask a further supplementary question. With the Productivity Commission confirming that, despite what the minister says, no country currently imposes an economy-wide tax on greenhouse gas emissions or has in place an economy-wide ETS, will the minister explain why Labor wants to continue with a policy that will disadvantage Australian businesses, hurt Australian households and have no guaranteed environmental benefits? Honourable senators interjecting— The PRESIDENT: All right— Senator Cameron: Simon, why did you backflip? The PRESIDENT: Senator Cameron! I call Senator Wong.