CANBERRA - The parliamentary defeat of Australia's carbon-trade laws has handed Prime Minister Kevin Rudd a trigger for an election from early 2010 to salvage his emissions trading scheme and key climate policy.

WHAT HAPPENS TO THE CARBON BILLS NOW?

* Rudd plans to re-submit his carbon trade laws to parliament again in February, at the end of a forecast sizzling hot summer, giving climate skeptics in the opposition another chance to support the plan. The government may be hoping expected summer heatwaves and bushfires will harden public opinion in favor of tough action to curb carbon emissions.

WILL THERE BE AN EARLY ELECTION?

* The government is playing down the option of an early election and Rudd has repeatedly said he would prefer to serve out a full three-year term. Regular elections for the House of Representatives and half the Senate are due in late 2010. This is the most likely outcome, given the carbon trade bills will be given one more chance in parliament.

WHAT ARE THE BENEFITS OF AN EARLY POLL?

* With the carbon laws twice rejected by a hostile Senate, Rudd has the option of a double dissolution, of the full Senate and House of Representatives, to clear the deadlock on the carbon bills. Rudd can now call a double dissolution election any time until August 11.

* If he wins, he can then push the deadlocked package of 11 bills through a special joint sitting of both houses of parliament, where he would normally have a clear majority. He cannot call a joint sitting after a regular election.

WHAT ARE THE RISKS OF GOING EARLY?

* An early double dissolution election would make it easier for Greens, minor party and independent candidates to win seats in the Senate, which could make life more difficult for Rudd in the long term.

* Rudd is a cautious politician, and he will be wary about going early. Current polls suggest Rudd would win. But polls can shift quickly and he could find it tough to sell a policy that is expected to drive up power bills and increase costs for business.

* The election of social conservative Tony Abbott as opposition leader on Tuesday further clouds the outlook. Abbott would be expected to have a honeymoon period of popularity in the opinion polls, making an early election a risk for Rudd.

WHAT ARE THE BENEFITS OF A LATER ELECTION?

* Rudd can call a regular election of only half the Senate and the full House of Representatives any time from July 1, 2010. A regular election would likely see Rudd's Labor and the Greens pick up Senate seats at the expense of opposition conservatives, giving Rudd a better chance of controlling the upper house.

* Rudd would be keen to deliver another budget in May, so his government can be seen to rein in spending, countering an opposition attack on his big spending government and economic management.

* A late 2010 election would also allow the government to run a major tax debate throughout 2010. The head of Treasury is due to report options for tax change later in December. A late election would allow the government to consider its options and to go an election with an offer of vote-winning tax cuts or major reforms.

Australia Tony Abbott