UK Political Editor MICHAEL SETTLE meets the UKIP leader who's never short of an opinion or two for an in-depth interview on Europe, immigration, and the independence referendum
It is an irony piled on top of another irony that Nigel Farage’s London office sits uncomfortably in Europe House, the headquarters of the European Commission which, in a previous guise, was the home to Conservative Central Office.
When I mention this, the UKIP leader points out that the Commission's London postcode even has the letters EU in it. "I'm not kidding," declares Mr Farage, his eyes rolling in disbelief.
Yet while he might be a political cuckoo in the EU nest, the ebullient politician appears to be sitting pretty.
Never in such media demand, UKIP's fortunes - in England, at least - are on the rise. Opinion polls have put the anti-EU party as high as 16%, while in a raft of by-elections last year it came second or third, replacing the Liberal Democrats as many voters' party of protest.
"Yeah, to have grown over the last couple of years in the opinion polls the way we have has been very gratifying but we have to prove that that's material and not theoretic. That's why the county elections (this year in England) are very important and the euro elections (next year across the UK) are crucial to the whole momentum thing."
Yet while momentum has been building south of the border, UKIP has barely caused a ripple in the Scottish political pool.
At the last euro election in 2009, it came sixth behind the Greens and polled under 5% and in the 2011 Holyrood elections, when UKIP proposed scrapping MSPs and replacing them at Holyrood with Westminster MPs, it did even worse and got less than 1%.
"Yeah, I have said Scotland has been a graveyard for us and that's because the entire national debate in Scotland has been a different debate and the word 'independence' has meant something entirely false and that's why I'm so pleased it's been exposed and we can now have a proper debate in Scotland about far bigger constitutional issues than the relationship between Holyrood and Westminster; far bigger than that is the relationship of both those institutions with Brussels and that's all changed.
"What's been very interesting over the last few months is that as UKIP has grown in the polls we've grown in Scotland too."
Like many others perhaps, I missed this development and ask what evidence Mr Farage has for this.
"Look at the regional breakdowns; look at YouGov, Comres, Survation, look at all of them. They vary and they fluctuate but we've been as high as 9% of the vote in Scotland. Given where we came from two years ago, it's a significant shift, a potential shift in support for UKIP in Scotland.
"I'm not pretending it's easy. We've managed in Wales, we got 15% in Wales, very credible, almost in line with our national percentage. We've had some little bits of electoral success in Northern Ireland. Clearly, the north of England has developed into almost as much as a powerhouse than the south of England for UKIP.
"The idea that perhaps people might have had 10 years ago that this is a sort of home-counties-retired half-colonels-who-were-jolly-angry (party), clearly that's changed already.
"The missing part of the jigsaw within the UK has been Scotland and that's because the debate hasn't allowed us in; there's been a different conversation going on."
He goes on: "I never, ever make rash or stupid predictions, I just don't - maybe comment and statements - and we are going to do everything we can in 2014 in the European elections in Scotland to get a breakthrough and to get elected representation in Scottish politics.
"We have proved in England that even with a small bridgehead, if your position is a good intellectual position, that is clearly arguable and events prove you right, you can build from a small bridge head into something that is quite significant in politics. I would say for UKIP in Scotland the 2014 European elections are the absolutely key."
The UKIP leader makes clear that if the party is to become any sort of political force in Scotland, then it has to succeed in the 2014 euro elections.
"So I'm putting it on the line. For UKIP Scotland, who have been a relatively small organisation and who have valiantly battled on, who in the last year and a bit have suddenly started to grow and attract some fresh talent, our campaign on wind farms and various things is suddenly bringing in new and different type people.
"But there has to be some realisable gain to keep any sense of momentum and any positivity within the party going forward; 2014 is the watershed for UKIP Scotland."
Unlike most politicians, who pause and nuance their remarks, trying to avoid controversy at any price, Mr Farage shoots from the hip and seems to revel in his forthrightness, laughing his tobacco-flavoured croaky laugh many times throughout the interview.
Yet the only time he hesitates and goes quiet is when I ask if 2014 - when pundits believe UKIP will attract the largest number of votes - could be a moment when British politics is realigned.
"I've wondered and thought about this for years...It's such a tough question to answer but I would just say this - some of the top line issues that are most closely and clearly associated with UKIP are of such enormous power as political issues across the political spectrum; the Thatcherite right will agree with them but very big sections of patriotic Old Labour feel the same on these questions too, that there is the possibility that we could do what the Reform Party of Canada did and do something dramatic and remarkable."
So it could be a mould-breaking SDP moment?
"Oh no, they got Blair. Blair was the first SDP Prime Minister. In fact, they're all bloody SDP. Cameron's SDP. The SDP achieved a total victory without actually winning themselves. This can manifest itself in lots of ways. In the case of the Reform party in Canada, they became the biggest party in the Canadian Parliament. So this can manifest itself in all sorts of different ways."
So is it possible UKIP could realign British politics?
"Again, as I said earlier, I don't make wild and silly predictions but I do think there is something very powerful in our headline issues."
One of which is immigration. The latest controversy that has flared up is about what might or might not happen from January 2014 - just four months before those euro elections - when the work restrictions on Bulgaria and Romania will be lifted.
The UK Government, having admitted to having its own estimate about a possible influx of migrants, then said it did not have one; the estimate in 2004 when Poland and other eastern European countries joined the EU turned out to be wildly inaccurate.
"They're in a mess," declares Mr Farage. "They're really scared because for years it was easy: Europe was over there, that was for intellectuals like Bill Cash and the Oxford Union; and immigration was over there and an entirely separate issue. Now in the minds of the public, they're coming together as one and the same and they're absolutely terrified of it.
"Every estimate that has been put out over the last 10 years on this, be it by the British Government, be it by the Romanian embassy, be it by whoever you like, has always been wrong by a factor of five or by a factor of 10 or whatever it may be. They're half hoping it will go away."
The UKIP leader produces a piece of paper and insists the declaration at the weekend by Coalition ministers that they can get tough with EU migrants wishing to take advantage of Britain's benefits system is pie in the sky.
"Cameron says any Romanian who comes and has appendicitis will die on the street and we'll all stand around and laugh. Within five hours of him saying it, Viviane Reding, the relevant European Commissioner, comes back and says sorry these are treaty commitments and she's right."
He refers to the habitual residency test where a migrant has to prove he or she is a job seeker, a worker, a student, a self-employed person or a self-sufficient person to qualify for welfare.
"Apart from pensioners, no one is excluded. What will not happen is Romanian pensioners will not be able to come and get old age pensions, that's clear. That's the one group of Romanians who will find access to direct benefit more difficult but absolutely everbody else that I can see can pass habitual residence. It's possible that they could under the law be made to wait three months. I completely concede it's possible.
"But if you come in and say I'm self-employed and I'm going to go and apply to be a Big Issue seller, you are by definition a self-employed person seeking work and you qualify on day one and not just for unemployment benefit but for housing benefit as well.
"There's nothing this mob can do about this because they have signed us up to be in a political union with countries who frankly...Bulgaria and Romania are not fit to be in a political union with us. I'm not stating that political point of view from arrogance or anything like that. I can fully accept we could be in a political union with France and Germany - I don't want us to be - but I can see why in many ways that might be a valid proposition on the table but with these former Communist east European states, countries who have not recovered..".
So talk of a crackdown by Iain Duncan Smith was just spin?
"The improbability of what's being said...is laughable. He was trying to stop people voting UKIP in the Eastleigh by-election. They're terrified. It's the biggest issue on the doorstep. I tell you why. When the Government said up to 15,000 a year from eastern Europe (would come), there are more than that in Southampton, and Eastleigh is a suburb of that. People down there are seeing social housing, a chronic problem in Eastleigh, and unskilled labourers getting jobs, just a nightmare."
Europe, of course, or rather getting Britain out of the EU, is UKIP's raison d'etre. When I suggest David Cameron with his promise of an in-out referendum had shot his party's fox, the Farage eyes bulge.
"If he wins the next election, no chance; following a renegotiation, not on offer; he will give us a referendum, heard it all before; cast iron Dave, why on earth would we believe him this time round and even if he means it, we have reached the point of 'cry wolf', nobody else believes him. The body language, the tone, everything about that speech dripped with insincerity from start to finish."
But it was a success politically because the putative rebellion by Conservative MPs has fizzled away, I suggest.
"They're tribal Tories, who gives a damn about them? Forget that building over there, let's talk about the housing estate a mile down the road, what's the impact been three weeks on? Zero.
"Far from shooting our fox what he has done inadvertently is to legitimise everything we have said for 20 years by putting it into the mainstream national debate; that there should be a conversation on in or out and, secondly, unwittingly and without wanting to he has let the genie out of the bottle.
"Rather like with the euro once we had a public debate on the euro public opinion swung against it. It was 50-50 in the 1990s, absolutely 50-50, people like me were thinking God almighty, they're selling us easier holidays in Spain, and maybe they're going to carry the day. But when we had the full debate after Blair, Heseltine and Clarke launched the Britain in Europe initiative, within 18 months we had a two-to-one majority against joining the euro and it's never changed since.
"The same is true of the bigger broader European debate, the genie is now out of the bottle, this can't be suppressed, there is going to be a debate on all four corners of the United Kingdom over the next year or two, or over the next five years, on this issue and that from my perspective is all to the good."
So, I suggest, that must lead to the referendum Mr Farage believes Mr Cameron, despite his promise, will not deliver.
"If UKIP closed down tomorrow, there would be no referendum ever. We could be here in 100 years. His backbenchers pose no threat to him at all. There isn't a single Tory backbencher who has said they would vote against their prime minister in a motion of confidence, not one. If we disappear, the referendum threat goes; if we stay, the referendum threat will be maintained. I very much believe that one of UKIP's very important jobs is to make sure that Labour make the same promise too - and they will."
Yet he acknowledges that the PM's speech was necessary to stop Tory MPs joining UKIP. "Had he not made that speech there would have been defections; yes, of course."
It is when I mention Europe in the context of the Scottish independence debate that I realise I have lit the blue touch paper. The development this week with Nicola Sturgeon insisting an independent Scotland would not need to sign a full accession treaty but simply amend the current one visibly ruffles the Farage forehead.
"There's nothing she has said on television that has impressed me. Frankly, she appears to be grossly out of her depth in the position she is in. Just for once, I'm going to go with Mr Barroso and not Nicola Sturgeon."
He continues: "At least Irish nationalism is a pure, honest form of nationalism. Scottish nationalism, which has been a fraud committed on the Scottish electorate for the last few decades, has finally been exposed as nothing more than what has now become its own political class, seeking to justify its own existence. There is complete intellectual and economic dishonesty in the SNP's arguments and I frankly have got no time for them at all, or her."
Mr Farage, who has previously acknowledged a sneaking respect for Alex Salmond - who has passed his 'would I have a pint with this person' test - says the First Minister played a good hand on independence "up until he was exposed".
He explains: "For a couple of decades, he played the hand incredibly well. He sold a completely false argument to the Scots, that you could leave Westminster and be independent and, in a little after-breath, be part of the EU.
"Gradually as time has gone on, it has become clearer and clearer to people in Scotland that being in the EU is completely inconsistent with the concept of independence and what sealed it is the European Commission President making clear that if you left the UK you have to reapply and sign a treaty that commits you to joining the euro.
"So that's what's changed everything and frankly the sheer dishonesty, the twists and turns, and the hiding of the report and all the things the SNP have done, they're doing themselves electorally huge damage."
So where does this leave the SNP's campaign for independence?
"It's finished already. I don't think the SNP proposal of Scottish independence as part of the EU flies, works, is logical; it's done, it's dead in the water. Far too many canny Scots have worked that out.
"If the SNP is able to reposition itself between now and the referendum, we can have this conversation again, but at the minute they appear to be in such a muddle and backtracking on everything, from the currency to the sovereign to...some idea this could be a treaty amendment, no, the irrationality of their position has been exposed."
I ask if he will, given his forthright pro-UK views, be an asset to the No campaign? He replies he will not be part of it.
"That's for Scottish UKIP to get involved in, it's not for me to get involved in. If I'm asked to speak in a university debate, I probably would. Am I going to be touring round Scotland in a referendum campaign on Scottish independence? No. UKIP Scotland can do that. I don't see that as my role particularly."
Yet UKIP is regarded as the Nigel Farage Party?
"Look, I have given, in so many ways, maybe illogically, the best years of my adult life in trying to make this point of view and this political brand an accepted, mainstream, genuine part of national British political debate.
"I've no idea why I've done it. I can't explain it. It didn't fit into my life plan at all. I've just done it and I've probably got more drive, more energy and more belief than most people who walk through the front door.
"But I couldn't have done it on my own. I couldn't have done it without thousands of activists and lots of people...There is a team of people behind Nigel that help to make this work now and without whom it couldn't have worked."
A politician referring to themselves in the third person is always interesting but, given the party's rising star, is he regretting not standing in Eastleigh?
"No. If Diane James does win, you boys will not go on saying we're a one-man party; that'll be ended. That blows a hole in that.
"It's my stated aim that I intend to lead this party as an active candidate into the European elections in 2014 and I want to cause an earthquake. I can't do that as a backbencher in the House of Commons.
"If we're going to get the momentum for something remarkable to happen in 2015, it can't happen without a big success in 2014 and right now at this moment in time, it could change, I'm the best qualified person in UKIP to lead that charge in 2014."
Soon, UKIP will be moving out of Europe House and into spanking new offices off Bond Street; the party's fortunes, it seems, are moving upmarket.