Tory politicians have called on Douglas Carswell to return to the Conservatives after he dramatically resigned as Ukip’s only MP.
Conservatives said that politicians who “make a mistake” should not be punished as they called on him to rejoin the Tories after a period as an independent.
The calls mark a dramatic about-turn for the Conservatives who fought to keep Mr Carswell out of Parliament after he defected to Ukip in 2014.
Andrew Bridgen, Tory MP for North West Leicestershire, told The Telegraph: “Douglas Carswell should return to the Conservatives after a period as an independent, he needs to rebuild a relationship with his local Conservative association .
“On the matter of whether he should return to the Conservatives, I don't think he should have ever left. If we punished every politician who made a mistake we would not have many politicians."
Former Ukip leader Nigel Farage tweeted that Mr Carswell "jumped before he was pushed" and that "he was never Ukip". Paul Nuttall, the current leader of the party, took a similar view and said he was "not surprised" and that "Douglas was genuinely committed to Brexit but he was never a comfortable Ukipper".
Mr Carswell said he left Ukip because the party "has now achieved what we were established to do" and headlined his blog post, in which he explained his decision, "Job done – thank UKIP!"
Paul Nuttall said that the party had "not benefited financially or organisationally from having Douglas Carswell in Westminster".
He also revealed: "On Monday, he had been due to meet with the National Executive Committee to answer various questions relating to longstanding issues, including published allegations that he had joined us in order to try and minimise Nigel Farage's involvement in the Referendum".
Mr Carswell wrote:
I will leave UKIP amicably, cheerfully and in the knowledge that we won.
I will not be switching parties, nor crossing the floor to the Conservatives, so do not need to call a by election, as I did when switching from the Conservatives to UKIP. I will simply be the Member of Parliament for Clacton, sitting as an independent.
I will be putting all of my effort into tackling some of the local problems affecting the NHS in our part of Essex... Local comes first.
Mr Carswell said that he will be leaving the party on amicable terms and that Ukip is "the most successful political party in Britain ever".
Carswell has jumped before he was pushed. He was never UKIP and sought to undermine us. He should have gone some time ago.— Nigel Farage (@Nigel_Farage) March 25, 2017
A Ukip source told The Telegraph: "He clearly doesn't want to have a party on his back telling him to do more work.
"Douglas will have more time now to tweet smiley faces and write an occasional book that no-one reads."
This comes after major donor Arron Banks left Ukip and announced he would be starting his own Eurosceptic political party.
He seemed happy about Mr Carswell's exit, expressing his feelings via emoji on Twitter.
Andy Wigmore, a spokesman for Mr Banks, said: “The net has been closing in – there is a Ukip national executive committee meeting on Monday and he [Carswell] knew he was for the chop, so jumped. He should call a byelection and Arron will stand against him.”
Douglas Carswell quitting shows UKIP now has no purpose. Theresa May is effectively their leader and has adopted their hard Brexit agenda— Tim Farron (@timfarron) March 25, 2017
UKIP parliamentary presence evaporates as the party continues its meltdown, they are fast becoming a busted flush...— Angela Rayner MP (@AngelaRayner) March 25, 2017
Ukip MEP Bill Etheridge, who had called for Douglas Carswell to resign, said he was "delighted".
"It's a lovely, sunny day and someone I believe was not genuinely interested in representing UKIP in Westminster but has been the focus of serious infighting in the party has gone.
"But I think he needs to step down and call a by election: he might think he can get away with not doing so because he is becoming an independent but I no more believe that than I do the moon is made of cheese. He was and is a Tory.
"He was elected twice on a UKIP ticket, with UKIP resources and the hard work and shoe leather of UKIP activists."
Mr Carswell said that people should not be dismayed that he has left the party, writing: "Cheer up! The days when small elites can try to arrange human social and economic affairs by grand design are coming to an end."
Ukip has been in an open civil war, with former leader Nigel Farage and Douglas Carswell at each other's throats.
Ukip souce adds re Carswell: "Douglas will have more time now to tweet smiley faces and write an occasional book that no-one reads"— Asa Bennett (@asabenn) March 25, 2017
Mr Farage, the former Ukip leader, said Mr Carswell had “sought to split and divide Ukip in every way imaginable” since defecting from the Conservatives to Ukip in 2014.
The two men have been at odds for years over the party's policies but their antipathy came to a head amid claims that Mr Carswell frustrated Mr Farage's chances of being awarded a knighthood.
He also appeared to mock the former Ukip leader's lack of a knighthood on Twitter.
Knight night. ��— Douglas Carswell (@DouglasCarswell) February 27, 2017
It was revealed by The Telegraph that after in which Mr Carswell was threatened with expulsion from the party, he had held secret talks with the Conservatives about joining them.
However, he has put those rumours to rest, writing: "I will not be switching parties, nor crossing the floor to the Conservatives, so do not need to call a by election, as I did when switching from the Conservatives to UKIP."
The new leader, Paul Nuttall hopes that with Mr Carswell's departure, the Ukip in-fighting will end: "As we redefine our mission and take up the next phase of our campaign to rebuild a confident, independent nation, Douglas would have been increasingly out of kilter with our members’ aspirations.
"We now have an opportunity to put behind us the most damaging internal conflict which has dogged us over the past year, and look forward with optimism and unity of purpose to the very real challenges of policing Brexit and further reforming the vigorous democracy of the UK."