WILLIAMS: On these streets in London, Mayor Boris Johnson is treated like a star - because he is. Today we're following him through the streets of Uxbridge in outer London, the electorate he's hoping and expects to win in the upcoming national election. 

[to supporter] "What do you like about him?"

SUPPORTER: "We just know that he's a very good person, a very good politician and I'm very happy to meet him here and to have a photo with him".

WILLIAMS: "What policy do you like the most about him?"

SUPPORTER: "Actually I have not much knowledge about policy".

WILLIAMS: "You just like his personality?"

SUPPORTER: "Yes".

Well this is Boris in the street, the entertainer, you can see he pulls a crowd. People want selfies with him. He's enormously popular because he entertains, but what about the essence of the man? What is Boris really like? What's he at his core and what's the political philosophy that drives him? Well if you ask many people here they don't really have that broader sense of him, just that they really like him. They like his positivity, they like the way he interacts with the crowd. They just like Boris. 

For many, Boris Johnson is an almost cartoon character, the blond beetle love-child. What other politician on earth could turn a zip wire disaster into a zany PR triumph? The seemingly hapless Bobbing Boris doesn't seem to mind if people laugh at or with him - as long as they like and vote for him - for behind the façade is a serious man with a belly full of ambition, not that he'll admit it.

"Everyone I talk to says one day at least you're going to have a crack at prime minister".

BORIS JOHNSON (MAYOR OF LONDON): "Yeah, yeah, yeah, yeah".

WILLIAMS: "Well?"

BORIS JOHNSON: "Well".

WILLIAMS: "That's the question. Do you want to be prime minister of Great Britain?"

BORIS JOHNSON: "What I want to do is I want to get elected in Uxbridge on May the 7th as a part of a winning conservative team that is led by David Cameron who amply fills the job of prime minister...."

WILLIAMS: "That's now, that's now, but at some stage in the future...".

BORIS JOHNSON: ".... and he's doing a great job".

WILLIAMS: "... at some stage in the future…".

BORIS JOHNSON: "Well I think I will be... I'll be a pretty decrepit old man by the time David Cameron relinquishes the reigns of office and there'll be all sorts of young thrusters, perhaps some of them getting their selfies with us today will be putting their names forward".

WILLIAMS: Today he's visiting the second most marginal electorate in the country, the seat of Hendon in outer London. The conservative incumbent is hoping the Boris stardust will help him hang onto his seat. 

INTRODUCTION: [at rally] "But without further ado, I'm going to introduce the Conservative Mayor of London, Boris Johnson". [cheers & applause]

BORIS JOHNSON: "Thank you very much everybody, good morning, good morning. Right we now have after five years of Conservative government, the fastest growing economy in Europe. Our city is the uncontested financial, commercial, cultural, artistic, scientific, sporting [laughter] and innovation capital of Europe".

WILLIAMS: Boris Johnson says a vote for the anti-immigration party UKIP or a return to Labour under leader, Ed Miliband, would be a backward step.

BORIS JOHNSON: "And I'd much rather by the way have the problems of today. I remember what it was like in the 1970s. You all look too young and thrusting to remember the 1970s. I was there! I remember and London was a much bleaker and more miserable place and it was a… we had a union dominated economy. We had something called the brain drain, do you remember? And we had hundreds and thousands of people leaving this country. We had such a hopeless economic situation - the population of London actually fell by two million".

WILLIAMS: Behind the Boris banter is a serious underlying philosophy, greed may not be good but making money, well, go for it!

BORIS JOHNSON: "And my advice to you, is vote Tory and get broadband, vote UKIP and get Miliband. [laughter & applause] That's the risk. And I think people look at what we're trying to do and they understand that we are supporting wealth creation, unashamedly but wealth creation with the moral purpose, with the moral purpose it is only if you have a strong and vibrant dynamic economy that you can pay for the poorest and the neediest and meet the civilised objectives that any society must and that's how we've won in London. That's how we're going to win again in London and that is how we're going to win in a few weeks time".

WILLIAMS: It's London where Boris has made his mark, 8 million and growing, 300 languages and cultures, 40% of those born outside the UK. According to the Mayor, it's a formula that can be successfully replicated across the country. 

BORIS JOHNSON: "I think that in London we've been very lucky because things are really going well and the economy's going gangbusters, but I think people have got to understand that that is because you know that we have a culture now in London of real enterprise and the start-ups are extraordinary. There's a confidence and there's an entrepreneurial spirit now that I think is at the heart of the economy".

WILLIAMS: He's pushing the idea of capitalism with "a moral purpose", prosperity to pay for schools and hospitals and a living wage of seven pounds and eighty-five pence an hour nationally - approximately fifteen Australian dollars.

BORIS JOHNSON: "Now you asked me what are the guts of my political beliefs. It's about backing wealth creation, backing energy and enterprise as the only way of getting to pay for the poorest and the neediest and so I'm not all socialist, I'm not a left winger because the emphasis there is treating the private sector as something you milk, something you loot, something you raid".

WILLIAMS: Boris Johnson sells himself as an action man on housing, employment and transport - the trains, buses and especially his beloved bikes. Perhaps what he's known best for is what I'm riding here. It's one of the bikes in the bike hire scheme sponsored at vast expense, millions of pounds by Barclays Bank. But do you think they're known as Barclay bikes? No way. These are known universally as Boris bikes. The Boris brand rules in this town, but can it rule further afield?

While London's chief cyclist harvests huge credit for the scheme, what else of substance is he peddling to the voters? 

"Well you're a great fan of Churchill of course with your book recently about it."

BORIS JOHNSON: "Yes."

WILLIAMS: "In one of those passages you described, or I think it was describing somebody else's description of him as "all sizzle, not much sausage". Could that accusation be levelled at you?"

BORIS JOHNSON: "No. I think that the sausage factor is almost overwhelming, ah if I may say so. The sizzle, if you look at the ratio of sausage to sizzle in London in the last few years, you know there is no other place… they have seen near Victorian levels of investment in their transport. They're seeing the huge expansion in sectors of the economy that didn't exist before. You know the sausages, I could… we have got so much sausage that you know Jeremy Clarkson himself will be weeping with joy with the sausage production that we've got going on here".

WILLIAMS: On the national stage Boris' greatest challenge will be immigration with almost all parties promising to cut the intake. Last year net arrivals increased to just under three hundred thousand - the majority from EU nations where free movement is guaranteed by law. It's a key election issue, dominating the debate and Boris Johnson has his own solutions in mind. 

BORIS JOHNSON: "What I would like, what I've campaigned for in the past is a free travel zone between Britain and Australia so that you have the same sorts of arrangements and just a recognition of, you know we're so timid in this country, we're so... we wouldn't say boo to a goose. We don't want to frighten anybody, we don't want to offend the European Union, we don't want to offend anybody. You know we've got a historic relationship with Australia. Now as it happens you know I think probably this is not the moment to offer any kind of you know change in any immigration policy at all. The whole subject's become so kind of toxic and neuralgic, you probably want to quietly park it for the time being but that's my feeling and I think there are many Australians in London who would agree with me. Whether they would be actually delirious with joy in Australia about the idea of loads more poms coming out to Australia I don't know so you know you need to work on that".

WILLIAMS: While his beloved London is regarded by most as a multicultural success story, in the stagnant rural and coastal areas, new arrivals are not always as welcome, creating deep fractures in society. It's seaside towns like Margate that are offering the anti-immigration parties their most passionate support. The once glorious holiday resorts are now beset by high unemployment and low economic activity. Indeed it's no surprise the head of the UK Independence Party, Nigel Farage, is running in Margate - supporters see him as a saviour, Britain's protector from the European Union regulations, and its unregulated hordes. He's here at the UKIP spring conference to rally the troops.

NIGEL FARAGE (LEADER, UK INDEPENDENCE PARTY): [addressing rally] "Only by divorcing ourselves from the EU and by taking back control of our borders can we give the British people what overwhelmingly they would want and support and we will campaign for this country to have an Australian points style system to decide who should come and settle in our country".

WILLIAMS: UKIP wants out of the EU and an end to the free flow of EU nationals - especially the Eastern Europeans. Anti UKIP protestors have come to the UKIP conference too with their take on the upstart party. But former immigration officer and UKIP candidate Maxine Spencer, dismisses accusations she belongs to a party of racists.

MAXINE SPENCER (UKIP candidate): "I'm an immigrant in terms of my mother's from Trinidad, my father's Welsh. I was born in London but left here as a little child and grew up in Trinidad so I'm sort of 50/50, so of course people say about racism, I think that's a load of rubbish. I know about racism, I sort of went through it as a child. I was born in the '60s in London and you know there were certain schools I couldn't go in because I was like a black kid".

WILLIAMS: She also wants Britain to adopt Australia's immigration system.

MAXINE SPENCER: "Immigration is a big issue for us but also I think it's the racist system they've got now. If you're a non EU national, you're subject to immigration control and if you're from the EU you're not. It should be the same for everyone. For me that's a much fairer system and I do admire Australia with the points system. It's really good because you know it's got a good system where it's controlled. It's just here it's not controlled enough".

WILLIAMS: Another UKIP candidate is 67 year old Peter Allen, a former plumber and a conservative voter until now, and thrilled to hear his leader speak.

PETER ALLEN (UKIP candidate): "Oh god it was so... well not just him but the whole day was so inspirational, instructional, that's the thing. It was a very successful meeting and yeah I enjoyed it. And yeah... I look to next year... I want to be here next year. I want to be up on stage next year".

WILLIAMS: But in the streets of Margate, a short walk from the UKIP conference, immigrants are breathing life into what were empty shopfronts. Stores like this former video shop were boarded up and now they house delicatessens selling Eastern European and other goods, providing employment and industry. 

KAZIMIERA DEREN: "I know they don't like Eastern European people but we are not going to move from here. I am living here for 11 years, some of my customers have been living here for 10 years. Many people have mortgages, what are we going to be doing with that? It's not fair".

WILLIAMS: Kazimiera Deren came from Poland looking for a better life. She says many immigrants have children in the local schools and mortgages.

KAZIMIERA DEREN: "If for example now, we go back to our countries who is going to work in here. We are helping to regenerate Margate and Clifton, especially Clifton, because it is an amazing place here and I hope no one will send us back to our countries".

WILLIAMS: UKIP is unlikely to win more than half a dozen seats in the House of Commons but the conservatives are neck and neck with Ed Miliband's Labour Party. Boris Johnson is well aware that if too many voters desert his party for UKIP, that will allow Labour to win more seats. But Boris Johnson, the best defence against UKIP, is to simply pretend it doesn't exist. 

BORIS JOHNSON: "I think the trick with UKIP is - as with all your people who try to imitate you - just ignore them. You remember John Travolta and Nicolas Cage in "Face Off"? Do you remember, did you see that film where they…I think one of them... Nick Cage freaks out because John Travolta steals his identity. Don't freak out. We're the Conservative Party, we're the only party that's going to offer a referendum on Europe, we're the only party that can conceivably form a government".

WILLIAMS: "And forget about Nigel Farage".

BORIS JOHNSON: "And forget them... just... why give them, you know, these other people, don't give them the oxygen. Don't give them the oxygen. Don't freak out".

WILLIAMS: As head of the UK Independence Party, Nigel Farage not only enjoys upsetting the political status quo, he's actually made a career out of it, cultivating the image of the political outsider - mad as hell and not taking it any more.

"It's always a bit of a scrum wherever Nigel Farage turns up. You can see the media throng around him now. People call him a xenophobe, a racist - he says he represents what Britains really want. The reality is, he is attracting enough votes to worry the major parties and that's why they are taking him seriously".

"Just one for Australia, one of Australia Nigel".

NIGEL FARAGE: "Hello, how are you doing? Well done in the cricket".

WILLIAMS: "What do you like about the Australian system?"

NIGEL FARAGE: "Well done in the cricket, well done with the points system, well done with making your own law, well done with being a self-confident nation and congratulations. And what do I like about it? You can choose! You can choose! You can choose how many people come to your country and you know you've set some very, very stiff markers in terms of qualifications, in terms of bringing health insurance and all of those things - that's exactly what we want for this country".

WILLIAMS: "Boris Johnson says the best way to deal with you and your party is ignore you both".

NIGEL FARAGE: "He can try if he wants to but there's a lot of people out there who aren't ignoring us and who intend to vote for us".

FARAGE MINDER: "Thank you, let's go."

WILLIAMS: Back in London it's a meeting of the very big fish, although one is witness to the other's final indignity. 

BORIS JOHNSON: [at fish markets watching large fish being chopped up] "What do you do with the head? You don't use that for Bouillabaisse?" 

WILLIAMS: The not so shy Mayor even stops to do international media interviews dressed as a fishmonger. 

BORIS JOHNSON: (referring to yellow boots, and protective cap) "I'd love to have them. 
My grandmother used to wear something like this sometimes. No, I have to wear this to protect the fish from any...you know, any mites or so forth that might crawl out from my head."

WILLIAMS: Boris Johnson's fish factory foray is aimed at encouraging apprenticeships and perhaps his own election chances, but he also has a message for London's apprentices learning the deadly arts of violent Jihad. 

BORIS JOHNSON: "All these kids, most of them are petty criminals, you know, lots of them are people's whose lives could be turned round at various stages in the chain and it's tragic in some ways that they haven't been, you know? It doesn't mean I blame society so to speak, I blame, you know, the parents, I'm afraid I blame... or I blame people who… the individuals themselves who must take responsibility and must be held accountable for what they've done. But yes, if you can get people into work then that will make a huge difference".

WILLIAMS: And it's a major concern for the Mayor that many young Jihadis, both men and women, come from his London.

BORIS JOHNSON: "Many of them will be the types of young people who will get involved in crime and gang stuff of all kinds. The thing is to de-mystify this. This isn't some spooky semi sacred thing going on here. These are guys who could become all types of criminals. They need to be… they need to be very tough law and order solution, you need a lot of police work on this. You need to crack down on them very hard, but you also need to make sure that they get employment, they get jobs and you know London is a great producer of employment. I want to see these kids feeling motivated, feeling included, feeling that society has something for them and you know what would be great would be for the, ah... for us all to work very hard so the Muslim community, everybody working together to say this is nothing to do with Islam, Islam totally rejects this whole jihadi nonsense, it's a mania, it's an ideological perversion, scrap it".

WILLIAMS: We're here in the idyllic village of Charing - it's about 40 minutes by train from London. It's the conservative stronghold that Peter Allen wants to win for the UKIP Party, both in the national and local elections. The former plumber has just returned from the UKIP conference in Margate, excited to be campaigning for his party. 

PETER ALLEN: [asking man in street] "What is it you like about it the most?"

MAN IN STREET: "I think basically the immigration part about it and I think it will make a change to have somebody different rather than the big boys". 

WILLIAMS: In this old world tea room in the high street, new world politics are discussed over scones and jam and cream.

"Boris Johnson has said of UKIP they're irrelevant, they're stealing our policies - just ignore them. Can you be ignored?"

PETER ALLEN: "No. No. There's such a groundswell now, really from the ground roots people. When I'm walking around I think... I get very, very little resistance to UKIP. There are people… "

WOMAN IN BACKGROUND: "I'll happily resist you over that."

WILLIAMS: "There's a lady over there in the corner there who's not quite agreeing with that at the moment".

WOMAN: "Absolutely not. What annoys me is the huge generalisations that you, and also people in the press talk about... So the last budget that came out last week, that wasn't widely reported on, was that the Office of Budget responsibility, part of their projections for economic growth was actually based on migration because migration at the moment has a net positive impact on GDP, and that was part of their figures. And the huge over- simplification that people like you have on immigration is enormously damaging. You have people from different countries and they all contribute in different ways, some of them do have benefits and there are others that come over and contribute enormously. And what the problem is, is you tar them all with the same brush".

PETER ALLEN: "You've obviously sat there listening and you realise that we're not trying to stop immigration in any sense at all. We welcome it. It's very useful for the country. What is not so useful is the fact that the open borders policy allows people to come here and not contribute but they're actually taking. What David Cameron was on about is a totally different thing. He was on about the legitimate people who come to the country and contribute".

WOMAN: "Because of the rhetoric you use, you talk about people coming over here and not contributing. The fact is most people do contribute and often when people don't contribute they end up going home if they can't get jobs".

WILLIAMS: "Can I just ask you a quick question? Do you understand the feeling of concern... it's amongst many, many people in this country... of a lack of control - too many people, just feeling a little overwhelmed in their own country". 

WOMAN: "I do, yeah I do understand that. I do completely understand that but what annoys me is that the whole issue is over-simplified and also sensationalised by the press and some parties that jump on it. And we need.... if we're going to discuss things, we need to discuss things based on facts and acknowledge the complexities of the situation".

WILLIAMS: "I take it you won't be voting UKIP?"

WOMAN: "Not in a month of Sundays, no".

WILLIAMS: "Thank you very much."

WILLIAMS: Out on the hustings, Boris Johnson says it's important to learn from the mistakes of the 1990s when he says immigration rates were far too high. He admits it's a key policy area to get right.

BORIS JOHNSON: "What you've got to do is here... you've got to make sure that you have policies that move away from Labour's uncontrolled immigration. They had a huge amount of illegal immigration in the 1990s and ah... right up till 2010. They let the brakes off and that did a lot of… I think people felt you know that the thing was out of control".

(CROWD AND PHOTOGRAPHERS MOBBING BORIS JOHNSON IN STREET)

WILLIAMS: But not everyone's bonkers for Boris. 

ALISTAIR CAMPBELL (FORMER ADVISOR TO PRIME MINISTER TONY BLAIR): "I do think there's an element of the kind of bumbling, slightly gauche, over the top.... this kind of pretty… it's an act, okay? I think often people say you know what you see with Boris Johnson is what you get. I think there is such a thing as fake authenticity and I think he's kind of got that".

WILLIAMS: Alistair Campbell was an advisor to then Prime Minister Tony Blair and has a longstanding disdain for the golden haired Mayor.

ALISTAIR CAMPBELL: "He definitely thinks he can go all the way to Downing Street and you know he's a man with a plan. I think it would be pretty bad for Britain if that happened. I think the idea that we as a country would elect somebody because they're funny, because they, you know, make mistakes and sort of bluster their way through it, I think that could be quite dangerous and I think it'd be very, very bad for Britain's reputation".

WILLIAMS: But despite some misgivings, Britain's conversation with this most ambitious of men may have just begun in earnest. The challenges of a nation may one day fall to him - immigration, the economy, Britain's place in the world. Some see him as a joke, but he may well have the last laugh.

SUPPORTER: "I like his enterprise, I like his intellect, I like his get up and go attitude. I like the way he doesn't..... well he's happy, he's prepared to knock down an icon, you know his spirit and I think underneath some of the inevitable clowning that he does, he's a very, very clever, very astute man. That's what I like about him".

WILLIAMS: "A future prime minister?"

SUPPORTER: "In time, but not yet".