MPs defections: a good career move which tends to form partof a wider political trend

Douglas Carswell has defected from the Conservatives to the United Kingdom Independence Party. He has taken the unusual step of opting to trigger a by-election, in effect asking the voters of his Clacton constituency permission for his decision. Alun Wyburn-Powell argues that MPs who defect tend to enjoy an enhanced career, and that their defection usually forms part of a wider trend – in this case the shift of voters from Conservative to UKIP