Why this will be a birthday to remember for David Cameron

The Clacton by-election will be held on 9 October - David Cameron's 48th birthday.

Ukip's candidate Douglas Carswell defected from the Tories last week and according to a Survation poll has a 44 point lead over other candidates. Looks like it will be a birthday to remember for the prime minister.

The Tories, who announced the by-election date today, are yet to announce their candidate.

More: Six Conservative MPs who are (probably) on Ukip's target list