SYDNEY: Australia's plans to become one of the first nations with a carbon trading system to cut greenhouse gas emissions were dealt a blow yesterday when the main opposition party dumped its leader who supported the idea and chose one who vowed to vote it down.

A tumultuous day in politics also means the country could also be one step closer to early elections, with policy differences over global warming placing it as a central issue of the coming campaign.

Debate in the Senate on the government's plans for an emissions trading system continued yesterday as the conservative Liberal party ejected one leader from the post and elected another. A final vote could come at almost any time.