Simon Crean 'prepared to cross the floor' on Labor's superannuation tax changes Labor MP Simon Crean says he opposes changes that could alter the tax treatment of people's superannuation. DUMPED cabinet minister Simon Crean has signalled he could be prepared to cross the floor on superannuation changes, saying he will do "whatever I can" to stop any retrospective measures coming into place. In his strongest comments yet on the lengths he is prepared to go to fight against flagged super changes, Mr Crean urged Prime Minister Julia Gillard and Treasurer Wayne Swan to reveal the detail on exactly what they plan do to the sector. "The sooner they spell it out the better for all of us," Mr Crean told the Nine Network's Today program. The Labor party elder, who was sacked by Ms Gillard from cabinet last month after calling for a leadership spill between her and Kevin Rudd, said he was open to "sustainable" changes to superannuation but would not back anything that raided contributions or earnings retrospectively. Mr Crean said he had never threatened to cross the floor on an issue in his long parliamentary career, but did not rule it out on superannuation. "I am prepared to do whatever I can to make common sense prevail, certainty prevail and a belief back in people that in us they have a government that not only is committed to their superannuation, committed to growing it but committed to making it sustainable," Mr Crean said. This has to be fought and it has to be fought on two fundamental grounds; one the test is, is it a retrospective application? If it is it needs to be rejected. Simon Crean has said he could cross the floor to oppose superannuation changes. Picture: Mark Graham Second do we need to make it more sustainable? Yes, but also on the basis that we continue to grow the adequacy of the superannuation pool. Defence Minister, and a member of the budget razor gang, Stephen Smith today said people needed to calm down on the issue of superannuation. "I think people should take a cold shower," Mr Smith told ABC radio. Former Howard advisor, now Liberal Senator, Arthur Sinodinos defended the opposition's stance that they may not be able to wind back any changes to superannuation if elected on September 14. He said it was the Coalition's jobs to criticise the flagged changes and they would oppose any move to raid superannuation. "As an opposition we have an obligation to look critically at all measures," he told ABC radio.