Tory MP Douglas Carswell defects to UKIP - full statement
28 August 2014 Last updated at 12:43 BST
Tory MP Douglas Carswell has defected to the UK Independence Party and will stand down as MP for Clacton to seek re-election in a by-election.
If he wins the by-election he will be the first UKIP MP to take a seat in Westminster.
He made his surprise announcement at a news conference in central London.
Mr Carswell told journalists: "Principle in politics is more important than the career of an individual MP, even when that MP happens to be me."