The prominent Eurosceptic Conservative MP for Clacton, Douglas Carswell has defected to UKIP. The decision was called a "political bombshell" by the BBC.
In a massive move for the Party, Mr Carswell told a press conference in Westminster this morning that his position with the Tories had become "untenable".
He told reporters that he thinks "many" other Tory MPs will now follow his move and join him in the UKIP ranks because the Conservative leadership was "not serious" about change in the UK's relationship with the European Union.
A by-election will now be held in Mr Carswell's Essex seat and he plans to represent UKIP when the poll is announced, standing on the core belief he shares with UKIP, that Britain would be better off outside of the EU.
Having announced the defection, a delighted UKIP Leader, Nigel Farage, said: "What makes this even the more dramatic is that Douglas Carswell aims to test this with his constituency.
"Douglas has joined a growing political force that is not a pressure group and is picking up support across the political spectrum."