By politics.co.uk staff
Ukip was in crisis today as one of its leading MEPs and former deputy leader defected to the Conservatives.
In a brutal parting note to his old party, David Campbell Bannerman said his colleagues in the European parliament "obsess with single issue politics, internal fighting, and shouting from the sideline".
The former Ukip chairman said the party "has confirmed it is not a serious, credible, fully fledged political party but merely a pressure group".
The MEP was previously a member of the Conservatives, standing as a Tory MP in 1997 and 2001.
The East of England MEP added: "Of course, I have not always seen eye to eye with the Conservative party on every issue. I continue to believe personally that Britain should leave the EU but I also believe that while we are members we should fight our corner to secure the best deal possible."
Foreign Secretary William Hague commented: "I am very pleased that we can welcome David Campbell Bannerman back to the Conservative party.
"I am sure David Campbell Bannerman will be a valuable member of our team in the European Parliament."
A statement released by Ukip read: "It is clear that David Bannerman has decided to put career before principle. He was obviously disappointed with his result in the leadership election last year, where he achieved 14% of the vote, and concerned about whether he could get re-selected by UKIP members in the Eastern Region.
"When he was chosen as a candidate for UKIP in 2008, David signed a statement that said that he would 'remain as a member of UKIP for the full five-year term or otherwise retire from the parliament'. We call on him to resign, so that we can get a real Eurosceptic to take his place."