Julia Gillard defeated Rudd in a leadership challenge and promised not to introduce a carbon tax, but would look to legislate a price on carbon when taking the government to the 2010 election. In the first hung parliament result in 70 years, the government required the support of crossbenchers including the Greens. One requirement for Greens support was a carbon price, which Gillard proceeded with in forming a minority government. A fixed carbon price would proceed to a floating-price ETS within a few years under the plan. The fixed price lent itself to characterisation as a carbon tax and when the government proposed the Clean Energy Bill in February 2011, the opposition claimed it to be a broken election promise.