Brown's dilemma

The prospect of an early election overshadows the UK Conservative Party's annual conference this Sunday.

Prime Minister Gordon Brown, wanting a mandate and wishing to capitalise on his early lead -- 11 percentage points, according to the latest poll -- is almost certain to call one earlier than he needs to. The question is: how early?

Brown and his allies have been deliberately vague on the timing, hoping to wrongfoot the opposition Conservatives. The argument for a November election is to prevent the Conservatives from throwing money at marginal seats between now and next year. On the other hand, Brown may wish to wait until after the EU reform treaty is agreed in October, in order to avoid a referendum on its ratification by running on a quiet election pledge to pass the treaty in parliament. Autumn days are also darker, which may discourage less motivated Labour voters from making a trip to the ballot box.

The decider may be the Conservative conference. If it sees sustained attacks on party leader David Cameron -- and some are already coming from the Tories' disgruntled Right -– then Brown will strike.