Australian Opposition leader Malcolm Turnbull. Photo / Getty Images

Australian Opposition leader Malcolm Turnbull. Photo / Getty Images

CANBERRA - Australian politics remains in chaos with the futures of Opposition leader Malcolm Turnbull and the Government's greenhouse emissions trading scheme hanging by slim threads.

If Turnbull falls and rebel Liberals block the ETS, Prime Minister Kevin Rudd could dissolve both houses of Parliament and call an early election that would likely hammer a divided and flailing Opposition.

The Senate, already running a day into its Christmas break, failed to meet Government demands to vote on the ETS legislation yesterday and will return on Monday to continue a bitterly divisive debate.

Government senators accused the Opposition of reneging on its deal to support amended ETS legislation, and said "whackos" and "climate change deniers" had taken control of the Liberal Party.

"It is deeply, deeply disappointing," said Deputy Prime Minister Julia Gillard.

But Opposition senators said the Government had no reason to demand such short debate on such a complex and far-reaching scheme, and said it was scared of allowing a full discussion.

Behind angry scenes in the Senate yesterday was Turnbull's increasingly parlous position, now appearing all but untenable with the defection of 13 members of the shadow cabinet, including some of its most senior and influential figures.

Key among them was frontbencher Tony Abbott, a minister in the former conservative government of John Howard, and until this week a Turnbull supporter in a battle that is tearing the Liberals apart.

Abbott has warned Turnbull to back down from his demand to pass the ETS legislation and instead follow party policy of deferring a vote until after next month's climate change summit in Copenhagen.

Abbott has called for another leadership spill and has said he is prepared to challenge the sorely wounded Turnbull.

But the position has been confused by reports that another powerful Turnbull supporter, Shadow Treasurer Joe Hockey, is about to switch sides and may try for the leadership if a spill - in which the leadership is declared vacant - is called on Monday.

Hockey, who yesterday continued to affirm his support for Turnbull, would then be faced with the same Catch 22 facing Turnbull: continue pushing for an immediate ETS vote with the gulf now dividing the party, or engineer a delaying vote that would start his leadership with a dangerous backflip.