CANBERRA - Australian Prime Minister Kevin Rudd has been handed a trigger for an early election, giving him the option of going to the polls any time from early 2010 in order to resolve a deadlock over his carbon trade scheme.

The carbon emissions trade scheme was a key plank of Rudd's political agenda and plan to curb greenhouse gas emissions, and was a central promise of his 2007 election win.

This is how the issue might now play out.

* Rudd's carbon trade laws are unlikely to be revived until after an election. Normal elections for the lower house and half the Senate are due in late 2010.

* But Rudd could call a double dissolution, of the full Senate and House of Representatives, to clear the deadlock on the carbon bills. 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.

* The most likely dates for an early election would be in March or April 2010. But Rudd is a cautious politician, and will be wary about going early. Polls suggest Rudd would win, but he could find it very 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 polls, making an early election a risk for Rudd.

* Rudd has said he would prefer to serve out his full term. That would enable him to focus on other reforms and deliver another budget in May. The government has planned a major debate in 2010 on tax reform, with the head of Treasury due to report options for change later in December.

* A snap election might throw economic policy up for grabs, with Abbott likely to campaign for firmer action against asylum seekers, more restrictions on trade unions, less government borrowing and potentially a firmer stand against gay marriage.

(Reporting by James Grubel)

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