Ukip's only MP, Douglas Carswell, is blocked from running for party leader after Nigel Farage resigns

Following his general election defeat in 2015, Mr Farage said it was credible for a party leader not to sit in the House of Commons

The relationship between Douglas Carswell and Nigel Farage (l-r) has soured since the former's defection from the Conservatives (Andrew Parsons / i-Images)

Ukip’s only MP has been barred from standing as its new leader.

The party’s ruling National Executive Committee (NEC) has said any candidate hoping to succeed Nigel Farage must have been a party member for at least five years - which rules out Clacton MP Douglas Carswell, who defected from the Conservatives in 2014.

Other leading Ukip figure, former welfare spokeswoman Susanne Evans who is temporarily suspended from the party for "disloyalty", will also be blocking from running.

Ms Evans said the decision was “ridiculous” and accused the NEC of “changing the rules as it goes along”.

She said: "I cannot imagine a decision more likely to bring Ukip into disrepute than one which means people such as Douglas Carswell and Mark Reckless, our current and former MPs, and the latter also a Welsh AM, cannot stand, despite the huge dedication they have shown to the party and their current elected positions.

"I hope the new leader will allow members to attend NEC meetings unless confidential information is being discussed; publish the minutes; and set up a 'right of recall' so NEC members are accountable to members”.

She accused it of “behaving like the EU” by “operating in secret” and “changing the rules as it goes along”.

Mr Farage announced he was stepping down as leader in the days following the referendum having declared his job was "done".

He previously resigned after failing to win a seat in the UK general election in 2015 saying it was not credible for him to lead the party without being in the Commons - before taking it back three days later.

The animosity between Mr Farage and Mr Carswell has been well documented over the past year with Mr Carswell accusing his leader of using “angry nativism” to attract voters during the campaign.

Mr Carswell, who unlike many in his party backed the official Vote Leave campaign rather than Leave.EU supporter by Mr Farage, has seemed at odds with his party at several points during his two years in the party prompting some commentators to suggest he may defect back to Conservatives.

He said he had received several phone calls making “grossly intrusive questions” about his marriage and there had been false rumours spread about him in his constituency in December last year.

The MP had already ruled himself out of the race for leader on referendum results night when he told the BBC: "I could not be a constituency MP. I could not be a dad and lead a political party. It would be bad for me and it would be disastrous for the party".

Nominations for the new Ukip leader opened on Monday and will close on July 31.

Candidates need to be backed by a proposer, need 50 supporters from at least 10 branches and must pay a deposit of £5,000 which will be refunded if they secure at least five per cent of the vote.

The declaration is due to be held on 15 September.