Civil war has broken out in UKIP as deselected West Midlands MEP Mike Nattrass branded leader Nigel Farage a ‘prat’ and threatened to spill the eurosceptic party’s secrets.

He also accused Mr Farage of rigging selection contests for next year’s European elections.

Senior party member Mr Nattrass, is a former UKIP deputy leader who has represented the West Midlands since 2004, hit out after he was barred from standing again in 2014.

He was told he had failed a selection process which was designed to weed out weaker candidates.

Speaking to the Birmingham Post, he said: “I am going to take on Nigel Farage. I’m not going to lie down on this, because it was a breach of democracy.”

But the MEP’s bid to take legal action to get the decision overturned has failed, after a judge in chambers concluded that it was not a matter for the courts.

UKIP insists the selection process was fair and candidates were selected or rejected on their merits.

Other West Midland hopefuls who failed to make the grade included Radio presenter Jon Gaunt, a UKIP member who was also rejected as a candidate.

Those who made it on to the candidates list included Bill Etheridge, who previously stood as the party’s candidate for police and crime commissioner in the West Midlands police force area.

He is a former Conservative council candidate who defected to UKIP in 2011 after being suspended from the Tory Party for posting a photo on Facebook which showed him posing with a golliwog doll. Mr Etheridge said the photo was intended as a protest against political correctness and censorship.

A total of seven candidates have been selected, as seven seats will be contested in the West Midlands region. UKIP activists will now be balloted to decide which order the candidates appear in on the ballot paper, with only those at the top having a realistic chance of becoming MEPs.

Mr Nattrass believes that potential candidates who were popular with rank and file members – such as himself – were deliberately excluded to ensure candidates favoured by Mr Farage came top of membership ballots.

UKIP succeeded in winning two West Midlands seats in the last European election in 2009. One went to Nikki Sinclaire, who is now an independent MEP after she fell out with Mr Farage.

Mr Nattrass remains a UKIP MEP but he too has turned his fire on the leader, claiming the party is becoming a one man band.

He said: “You’ve got to have a party which is represented by many people not just one.”

And he intended to reveal details of the party’s operation which would embarrass Mr Farage, he said.

“I’m not going to walk away just because some prat has decided that they don’t think my face fits.

“Well I’m sorry but I think we need more people like me whose faces don’t fit so we can have democracy and free speech.

“If there’s a vote and there are 20 people in the room and I say something that’s taken to be outrageous then obviously I’ll be voted down.

“But most of the time people come round and say actually that was a good point.

“So my points are not outrageous, it’s just that Nigel doesn’t like them. I’m a thorn in his side.”

Mr Nattrass, who was UKIP’s deputy leader from 2002 to 2006, publicly clashed with Mr Farage in 2010 over UKIP’s decision to join a controversial faction within the European Parliament called Europe of Freedom and Democracy. This includes Lega Nord, an Italian party sometimes known as Northern League in the UK, which advocates autonomy for the north of Italy.

He also expressed some support for Ms Sinclaire during her battles with the party.

But the selection process had been rigged to ensure the candidates picked were willing to do what they were told, he said.

“It doesn’t just impact on me, it impacts on a range of candidates who have been excluded because they take the focus off the chosen ones.

“The chosen ones are those selected by Mr Crowther the chairman, who denies Mr Farage is involved. But that seems strange to me because people have told me that Mr Farage told them they would be on the list of candidates, and lo and behold they were.”

The “chosen ones” were “people who are prepared to do service to Mr Farage,” he said.

Other candidates who might have won the support of party members – placing them high on the list of candidates presented to voters in the European elections – had been excluded, Mr Nattrass said.

“We have the chosen ones on the list and then gonks or people who have never been heard of.

“It is not good. I still support the principles of UKIP but this is not the way to run a political party. We are going in the wrong direction.”

Mr Nattrass said he was regularly asked to speak at UKIP events across the country, and was backed by party members in the hustings that formed part of the selection process.

“I went through hustings, which took place at Great Barr, I got a round of applause before I spoke – apparently I was the only one that got that. So I am popular, believe it or not.”

But he had been told by Mr Farage that he failed the interview portion of the selection.

“What Nigel Farage is saying is, he wrote to me when I complained and said I had failed the interview.”

“It was a stitch. The interview panel were sent to nobble me.”

Mr Nattrass, a chartered surveyor and businessman originally from Yorkshire, said he had a different lifestyle to Mr Farage, a broker from Kent whose father was also a broker.

“My habits are not similar to his. I’m not a drinker. I don’t go to the pub all the time. I’m prepared to go down there and have a meeting with people. But I’m not in his in crowd, I don’t do the things that he does.”

Warning that he planned to reveal more about the way Mr Farage ran the party, Mr Nattrass said: “I’m going to make sure that people know who he is.”

A UKIP source said all candidates were treated equally. Sitting MEPs had to go through the same process as everyone else and were not automatically re-selected.

A spokesman highlighted the failure of Mr Nattrass’ legal challenge, saying: “We are very pleased with the result.

“The judge made it perfectly clear that the system for all candidates was fair, and was designed to be fair.

“We now get on with the job of selecting the best candidates to represent UKIP and the country in the European Parliament.”