The Prime Minister Kevin Rudd, along with Treasurer Wayne Swan and Climate Change Minister Penny Wong, called a press conference in Canberra at lunchtime today.

They announced a 12-month delay to the start of the scheme, along with new targets and fixed price measures to help ease in the new package.

Mr Rudd told Canberra journalists the Government's carbon pollution reduction scheme would now be phased in from 1 July 2011 and a new "ambitious" target to reduce emissions by 25 per cent of 2000 levels by 2020 would also be introduced.

Mr Rudd said the delay was to predominantly manage the impacts of the global recession, announcing further assistance measures of a $10 cost for carbon permits for the first year of the scheme, and a new Global Recession Buffer package to intensive trade exposed industries.

The Government is also keen to add to the momentum for a new global agreement on greenhouse emission reductions at Copenhagen and has committed to reduce carbon pollution by 25pc by 2020 if the world agrees to an ambitious global deal.

Mr Rudd said should the world achieve this agreement the Government would put the case for increased 2050 targets to the people at the next election.

"We have listened to calls from the business community for a later, more gradual start to the Carbon Pollution Reduction Scheme and additional assistance to manage the impacts of the global recession," Mr Rudd said.

"This package of measures strengthens our response to climate change, ensuring Australia plays its part in global efforts to tackle climate change while managing any impacts on the economy."

The Greens and Coalition had both signalled they would not support the initial legislation, and there had been a rise in calls for new economic modelling to determine the impact of a scheme and whether Australia could afford a scheme given the collapse in world economic conditions.

Today the Greens have struck a deal with the Government to help the legislation get passed.