Nigel Farage wants to be taken seriously.

For too long, UKIP has been seen as a single-issue party, obsessed with Europe and silent about other issues.

That made it a natural home for retired colonels in Tunbridge Wells and allowed it to do well in European elections, when voters wanted to protest about waste and bureaucracy in Brussels.

But UKIP is set to enter the mainstream, if Mr Farage has his way. He believes he is on course to win seats at Westminster – and might even hold the balance of power after the next General Election.

And he has a plan. His unlikely role model is Paddy Ashdown, the former Liberal Democrat leader who in the 1990s steered his party out of the wilderness (following a disastrous merger between the old Liberals and the SDP) and made it a force to be reckoned with again.

Ashdown refined the traditional Liberal and Lib Dem tactic of building up strongholds in local elections and using these as a launchpad for general election success. The election of a cluster of Lib Dem councillors in neighbouring wards would lead, eventually, to the election of a Lib Dem MP.

It’s a tactic that eventually propelled the Lib Dems into Coalition government. So why shouldn’t it work for UKIP?

Mr Farage revealed his ambitions, as he spoke to the Birmingham Post at Westminster.

He also announced that he was open to the idea of standing joint candidates with other parties, as long as the candidate was a genuine eurosceptic – and named Lichfield MP Michael Fabricant as one of “the good guys” that UKIP would endorse, in the unlikely event that the Tory leadership allowed such a deal to proceed.

Of course, the potential fly in the ointment for Mr Farage is the fact that David Cameron has already announced that Conservatives will offer a referendum on quitting the EU if the Tories win the next election – and a Bill sponsored by backbench MP James Wharton, guaranteeing a referendum, is soon to be debated in the Commons.

While Mr Farage may insist Europe isn’t the only reason for backing UKIP, clearly it’s an issue many of his supporters care deeply about. So why vote UKIP if the Tories are already offering a referendum?

His answer is simple – nobody, he says, believes Mr Cameron really will hold a referendum and the Bill making its way through the Commons means nothing, because Parliament could just repeal it after the next election.

“It’s utterly irrelevant rubbish,” he says. “No Parliament can bind its successor. The legislation isn’t worth a hill of beans.

“It’s merely a method to prop up the fact that nobody believes a word David Cameron says.”

UKIP has enjoyed significant election success recently, coming second in by-elections in Eastleigh and South Shields.

But this is more than just a protest vote, Mr Farage insists.

“We have changed the political debate in Britain.

“The idea we should not be part of the EU is now a respectable mainstream debate. Immigration is now a respectable mainstream debate.

“In fact, having not talked about it for 30 years they are now all talking about it. There is almost a bidding war going on now between Cameron, Miliband and Clegg for who can be the toughest on immigration. Some of their right wing rhetoric really worries me, I can tell you.”

UKIP would present the European elections taking place on May 22 as a chance for voters to tell every party leader that they wanted a referendum, he said.

“I think that it’s a realistic thing to say that UKIP could win the European elections next year, and that would be an earthquake in British politics.”

UKIP leader Nigel Farage
Farage believes UKIP's performance in recent local council elections put them in with a chance of a seat in Westminster

But perhaps surprisingly, he’s actually more interested in doing well in the council elections taking place on the same day.

“But the clever bit for us next year us not winning the European elections, it’s the nearly 6,000 seats up at the same day on district council level and unitary level all over the country.”

The aim is to win “many many hundreds of seats at local government level” – which could provide a springboard to general election success, he said.

“Paddy Ashdown proved one thing. Whatever one thinks of Lib Dem politics, Ashdown was a brilliant leaders of the Lib Dems. And they focused on building up by winning by-elections, by building up clusters of district and county council seats.

“And once you hold a number of council seats that you’ve won under first-past-the-post at local level, the perception that you are a wasted vote and you can’t win at Westminster level disappears.”

This is the approach he hopes to emulate, he said.

“Lets say, for argument’s sake, in 2015 we spend our entire resources on 50 or 60 seats We target ruthlessly and we attempt to get unto the House of Commons in significant numbers and who knows, maybe hold the balance of power. So that’s where I intend to take this thing over the next couple of years.”

UKIP has been the subject of overtures from Tory MPs including backbenchers Nadine Dorries and Jacob Rees Mogg, as well as Michael Fabricant, the Lichfield MP and vice-chairman of the Conservative Party who suggested the two parties could agree an electoral pact.

Mr Farage says he is all for it, as long as the MPs in question are sincere in their euroscepticism, although as he correctly points out, the Tory leadership has already ruled a deal out.

“It is now legal that one candidate can have the official logo of more than one party.

“Nadine says she wants to run at the next election with a Conservative logo and a UKIP logo. Jacob Rees Mogg has more or less said the same thing, Fabricant has more or less said the same thing.

“How do I feel about that? Yeah, why not?”

But he adds: “While Dave is leader of the Conservative Party, I think all this speculation about deals, frankly I don’t think it’s going to happen.”

Asked if UKIP would consider simply not putting up candidates against right-wing Tories, he takes umbrage.

Opposing the EU is not right wing, he says, highlighting Labour eurosceptics such as Frank Field and Birmingham MP Gisela Stuart.

“Is Frank Field right wing? Is Gisela Stuart?” He adds: “This is nonsense, this idea that being eurosceptic and believing in parliamentary democracy and governing yourself... it is not right wing.”

UKIP is a “classical liberal party” he says, believing in the free market and opposing state intrusion into people’s lives.

But he accepts that the party has far more to do to explain what it does believe in, other than quitting the EU.

The 2010 election manifesto, which included proposals such as subsidising private school fees and increasing student grants, was “a Horlicks”, he admits – pointing out that he wasn’t leader of the party at the time.

But asked to set out some of his party’s policies, he comes up with proposals which were part of the 2010 platform, including creating more grammar schools and upgrading both the East Coast and West Coast Main Lines (to be funded by scrapping HS2).

There’s “a lot of work” still to do, he admits.

But if the transition from single-issue party to a real party of government is difficult, it is one he is determined to make.

Nigel Farage isn’t going to go away and he isn’t going to be silenced, as he makes clear when we discuss whether UKIP will be allowed to take part in televised debates during the next general election.

“If they want to exclude us from the debates that’s fine. I will hold open air public meetings at the same time, on the same night, in those towns and we’ll probably get even more coverage from it.

“They can’t any more brush us under the carpet and think we’re going to go away, we’re not.”