Tory defector Douglas Carswell has defended his decision to join Ukip and said he hopes voters will stick with him.
Mr Carswell and his new boss Nigel Farage began their charm offensive in Clacton, the constituency they hope will provide Ukip's first MP.
Chancellor George Osborne described the defection as regrettable. But as the MPs resignation became official this afternoon, there were even stronger words from the candidate who was originally due to represent Ukip in Clacton.
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The resignation of Douglas Carswell as Clacton's Member of Parliament has become official a day after he announced he was defecting from the Conservatives to UKIP.
By parliamentary convention set in 1624, MPs can't actually step down from office. Instead they have to apply for one of two offices of the Crown which are incompatible with being an MP.
So on Friday afternoon a message was released by HM Treasury which made Mr Carswell's resignation official:
"The Chancellor of the Exchequer has this day appointed John Douglas Wilson Carswell to be Steward and Bailiff of the Manor of Northstead."
Douglas Carswell has been a Conservative MP since 2005, first as the MP for Harwich and then, after boundary changes, for Clacton.
He announced on Thursday he was quitting the Conservative Party to seek re-election as a UKIP MP in a by-election.
It's not known when the by-election will be held but it usually takes place within three months of there being a vacancy. The date will be decided in Parliament by the Conservative Party Chief Whip, Michael Gove.
Ukip's Roger Lord has said he has no intention of stepping aside for the Conservative defector Douglas Carswell.
The existing general election candidate in Clacton-on-Sea said he 'will not back down'.
George Osborne has labelled the defection of Douglas Carswell to Ukip as "regrettable and counter-productive".
Speaking in Brighton today, the Chancellor said that the best way to secure a referendum on Britain's membership of the European Union was to have a Conservative government after the next election.
"That's the choice people are going to face, whether it's at the by-election in Clacton or at the general election next year," Mr Osborne said.
Tory defector Douglas Carswell said "I stab people in the front, not the back" as he defended his decision to quit the party.Read the full story ›
Nigel Farage, the Ukip leader, and the party's new candidate for Clacton have been campaigning on the streets of the seaside town this morning.
Douglas Carswell will contest the seat for the eurosceptic party after defecting from the Conservatives yesterday, triggering a by-election for the constituency.
Nigel Farage has reiterated more Conservative and Labour MPs are set to defect to Ukip following Douglas Carswell shock move from the Tories.
While on the campaign trail with Mr Carswell in Clacton this morning, Mr Farage said he expected more to jump ship if the Tory defector wins the by-election.
Mr Farage said, "Let's see what happens in this by-election, but if Douglas wins this by-election there'll be others - not just in the Conservatives but on the Labour backbenches too".
Conservative grandee John Redwood has dismissed the "so-called" eight Tory MPs allegedly considering defection to Ukip as "figments of Ukip's imagination".
"Dream on Ukip," the eurosceptic MP for Wokingham and former Wales Secretary told Radio 4's Today programme.
"I treasure the words of Mr Carswell which he was speaking yesterday. He said that we need to deliver an in-out referendum, he said it would only happen if David Cameron was prime minister," Mr Redwood said.
"He said we must do nothing to make the prospect of a referendum less likely. He was super-loyal until yesterday."
Ukip leader Nigel Farage and his new recruit Douglas Carswell are in Clacton as the pair plan a completely unexpected by-election campaign.
They are visiting the seat after Mr Carswell's bombshell decision to switch parties and quit the Commons to re-stand under the Ukip banner.
Ukip's general election candidate for Clacton has vowed to fight Douglas Carswell for the party's nomination in the upcoming by-election.
Roger Lord said he would "absolutely" fight for the nomination. "I have been assured I will get a fair hearing," he told Radio 4's Today programme.
Asked whether he would step aside to make way for Mr Carswell, Mr Lord replied, "We are not a party that stands down. We don't bend, we don't break. We fight."
Mr Lord also accused Mr Carswell of jumping ship from the Conservatives because the water was "around his ankles".