"Our main criticism is that the package of measures is simply not enough. We hope the government is going to improve it," said Gerhard Timm of the BUND group.

BUND and its fellow pro-climate group Greenpeace say the main measure the government needs to adopt is a ban on building any more coal-fired power stations.

"There are currently 27 power stations being planned across Germany," Timm said.

If they are all built, he said, they would account for an increase in carbon dioxide emissions that would wipe out any progress made to cut emissions.

Chancellor Angela Merkel and her coalition government of conservatives and Social Democrats will meet on Thursday and Friday to finalise a number of government policy dossiers, including the global warming initiative.

The proposed measures are expected to include more efficient energy use in homes, 'greener' cars, as well as raising the percentage of electricity produced from renewable sources to between 25 and 30 percent by 2020.

Under Merkel's leadership, the European Union set a goal in March to cut emissions to 50 percent below 1990 levels by 2050.

Member states at a summit of the Group of Eight most industrialised nations in June in Germany agreed a non-binding goal to halve greenhouse gas emissions by 2050.