Senator BIRMINGHAM (South Australia) (14:31): Mr President, I ask a supplementary question. Given the CPRS was forecast to run at a deficit reaching $1.6 billion in 2013-14 alone, and the government is promising more household compensation under the new carbon tax than under the CPRS, will the minister guarantee that a budget-neutral carbon tax will have no negative impact on the budget bottom line in each and every year of the forward estimates?