Former leader Nigel Farage has taken a fresh swipe at Ukip's only MP, saying that Douglas Carswell "shouldn't be in the party".

Mr Farage also took aim at the party's deputy chairman Suzanne Evans, saying she had an "overinflated opinion of herself" and he did not rate her highly.

In an interview on LBC radio, the ex-leader repeated his promise not to be a "back-seat driver" to his successor Paul Nuttall, but did not rule out standing for Parliament again if there is a re-run of the Thanet South election.

Kent Police and the Electoral Commission are currently investigating whether Conservatives broke the law by failing to declare tens of thousands of pounds of hotel bills for activists during the general election campaign in the seat, where they saw off a challenge from Mr Farage.

The probe could lead to the result being declared void, forcing a fresh election in 2017, though the party maintains that it acted "entirely within the law".

Mr Farage has previously indicated he would fight a re-run poll, which he lost by 2,812 votes in 2015.

But he told interviewer Nick Ferrari he was now not sure whether he would run for Parliament again, saying: "Let's see what happens in Thanet. I don't know. Right at the moment I'm enjoying life. I don't have to wake up every morning thinking about the next set of elections next May."

Mr Farage initially hailed Mr Carswell's 2014 defection from the Tories as a triumph, but relations between the men have since soured.

The ex-leader told LBC: "He shouldn't be in the party. He doesn't believe in what we stand for, he never has done ... Since the general election all he's done is sought to undermine us and divide us. And I notice even since Paul's become leader we've had some statement from Carswell saying that he thought Theresa May's doing a fantastic job."

Mr Farage suggested that Mr Carswell had been equally out of place in the Tories, telling Ferrari: "Last year at a Christmas cocktail party I bumped into David Cameron ... We chatted and he said, 'Tell me, Nigel', he said, 'How are you getting on with Douglas Carswell?' I said, 'About as well as you did'."

Asked whether the former prime minister had laughed at his comment, Mr Farage said: "He did. There are some people who just don't fit in anywhere ... I think Douglas is an individual. He's got his own set of views on things but maybe party politics isn't really for him."

Mr Farage dismissed suggestions that there had been a "vendetta" against Ms Evans, who was an ally of his when she wrote the party's 2015 general election manifesto, but was later suspended over comments she made about his "divisiveness".

She was restored to the role of deputy chairman by Mr Nuttall after he beat her in last month's leadership contest.

The former leader acknowledged that Ms Evans was "capable" but played down her role in the manifesto, saying she had "project-managed" the document for him and done the job well, but that it had given her a "ridiculous, I think rather overinflated, opinion of herself".

And he repeated his criticisms of Diane James, who led Ukip for 18 days before quitting in October, describing her decision to walk away from the job as "a selfish act".

Mr Farage said Ms James's departure was "a bit of a hiccup, to say the very least" for Ukip, but the party was now "in pretty good hands" under Mr Nuttall.

The former leader said he was ready to help out his successor, but insisted: "I'm not going to meddle, I'm not going to interfere."

His advice to the new leader was to "be himself" and not "try and mimic or copy the way that I did things", he said.

And he signalled his approval of Mr Nuttall's strategy of trying to "replace" Labour as the party of choice of working-class voters in the Midlands and the North, saying: "I think the Labour Party's in terrible trouble with its traditional old Labour working class ... base and I think Paul is the perfect person to really go after that vote."

Mr Farage also had harsh words for former chancellor George Osborne, accusing him of "utter dishonesty" in his presentation of the Tory economic record at the general election and "despicable" in his attempts during the referendum to persuade voters that Brexit was not in their financial interests.

"To try and frighten the life out of people financially the way in which he did and using precise figures as if to say 'I know what's going to happen' I thought was absolutely despicable," said Mr Farage. "Very pleased to see the back of him."

He said he hoped never to see the former chancellor back in office, predicting: "He's basically going to rebrand and remodel an Edward Heath. He's going to sit on the back benches and be bitter and twisted for the rest of his career."