Senator BIRMINGHAM (South Australia) (14:29): Mr President, I ask a further supplementary question. How does the minister explain downplaying the budget impact of a shift to the floating price in 2015-16 when questioned by the opposition compared with her willingness to argue in response to changes suggested by Mr Rudd than an earlier floating price would be likely to have 'a very negative effect on the budget'? Why has the minister only been open about this risk when it allowed her to rebuff Mr Rudd's leadership plans?