They say that unless rich countries make this commitment, developing countries will not be able to make the cuts needed to clinch an international climate change deal.
The international push for a tough Australian regime comes as cabinet's climate change subcommittee met for the second time, with the Rudd Government struggling to finalize its emissions trading scheme and hose down domestic business concerns about its impact on top of the deepening global economic crisis.
South African Environment Minister Marthinus van Schalkwyk said that "Japan, Russia, Australia and Canada have avoided putting their numbers on the table for too long. They now need to come forward with credible and ambitious mid-term targets within the 25 per cent to 40per cent range for 2020.... Without such an unambiguous commitment, it will be very difficult to engage developing countries in a credible way to make their deviation below baseline substantial.
In its submission to the negotiations in Poznan, China called on developed countries to make cuts of at least 25 per cent.
Climate Institute chief executive John Connor seized on the comments as proof that "there is no point in Australia turning up in Poznan without a commitment to cut domestic emissions by at least 25 per cent".
But Australian electricity suppliers and business groups say that 25 per cent is not achievable, insisting the Government should announce cuts of between 5 and 15per cent of 2000 levels by 2020 when it unveils the final scheme on December 15.
"When we modelled a 20 per cent cut, it resulted in the closure of about 25 per cent of Australia's coal-fired power stations in the next decade; we think a 25per cent cut would be almost impossible to achieve," said Electricity Supply Association of Australia chief executive Brad Page.
The Department of Climate Change has spent the past weeks negotiating with individual businesses and companies about what compensation they could be offered, either in the form of getting emission permits for free, or of direct grants from the Government's proposed Climate Change Adjustment Fund.
The Government has already indicated it favours a "soft start" to its scheme, modelling cuts of between 5 and 15 per cent, but its adviser Ross Garnaut said a 25per cent cut could be possible in the "unlikely" event of a quick and ambitious global deal.