Destiny: The Prime Minister, David Cameron, knows that he has just 18 weeks until the General Election to drill home his message – or see his political career finished 
 
 At 30,000ft above Cornwall, flying towards a crucial Election battleground, immaculate in suit and blue tie, it is strange to hear the Prime Minister talk about cleaning out stinking drains over Christmas. 
 
 A domestic emergency forced David Cameron to roll up his sleeves and stick his arm down a U-bend in the pipes at his Oxfordshire house. 
 
 ‘Unblocking a lot of drains is not my strong suit but the kitchen, bathrooms, everywhere... our house is falling apart,’ he explains. 
 
 The British economy will be a trickier fix, he acknowledges, and DIY Dave’s mantra is that only he has the tools to save us. 
 
 The Prime Minister knows that he has just 18 weeks until the General Election to drill home that message – or see his political career finished before he is 50. Worst of all, he would go down in history as the man who lost to Ed Miliband. 
 
 Launching his bid for another five years in Downing Street in an exclusive interview with The Mail on Sunday, Mr Cameron: 
 
 Vows to ‘hit the ground running and hard’ if he is re-elected, introducing reforming legislation on education and welfare within the first 50 days. 
 
 Warns German Chancellor Angela Merkel ahead of discussions this week on Britain’s future in the EU that he is prepared to take Britain out of Europe, saying: ‘If I don’t get what is needed, I rule nothing out.’ 
 
 Is so close to the American President that Obama calls him ‘bro’. 
 
 Reveals that he authorised the removal from the Tory candidates list of an aide to Home Secretary, and future leadership prospect Theresa May. 
 
 Tells Boris Johnson that he will have to wait for a Cabinet seat. 
 
 And claims that Labour’s budget plans will cost £13.5billion extra just in interest payments on the deficit, more than the police budget. 
 
 As he surveys the green patchwork of fields and villages across the United Kingdom where he needs to win enough votes to avoid disaster, he says starkly: ‘The choice is competence or chaos.’ 
 
 Drain duty aside, Cameron had a very merry Christmas. He cooked, went for bicycle rides and long walks (‘to run off the mince pies’), played winter tennis with his son Elwyn on the court which Tony Blair had specially renovated, found Downton Abbey too long but watched a re-run of Out Of Africa with four-year-old daughter Florence falling asleep on his lap (‘nothing nicer in the world’). 
 
 There was only one major work interruption, a quick dash to London over ebola. After turkey at Chequers, it was home to Chipping Norton. 
 
 As Father Christmas (he claims that all his children, even his ten-year-old daughter, still believe), he delivered stockings. 
 
 ‘We always, on Christmas morning, have the stockings opened all in our bed. It’s my favourite hour of the year.’ 
 
 His gift from his wife Samantha was a casserole dish – ‘we exchanged practical presents’ – while he gave her the latest Nick Hornby, Funny Girl, before immediately borrowing it back. 
 
 Scroll down for video 
 
 Passionate: The Prime Minister, right, spells out his plan to to The Mail on Sunday editors Geordie Greig, left, and Glen Owen 
 
 What has not changed is his quirky music sense. Two years ago, it was a Swedish folk band, First Aid Kit. His new favourite is Nick Mulvey, a folk singer who trained in President Castro’s Cuba – ‘a bit grungy, I admit’. Picture the PM in apron, stirring the beef bourguignon in time to a song called Cucurucu. 
 
 A big change in the Cameron holidays this year was that he was also chief supervisor for the children’s homework. He discovered the modern way of calculating long division and hated it. 
 
 ‘What was wrong with the old way?’ he asks. It is clearly something his new Education Secretary Nicky Morgan may well be looking into. 
 
 This is the most important Election for a generation, a real choice between continued competence or disaster David Cameron 
 
 ‘It’s very confusing as suddenly your children look at you and say why are you doing it in a totally different way.’ 
 
 His Christmas reading was dominated by Do No Harm, a frank memoir by Henry Marsh, an outspoken brain surgeon, whose opening line is: ‘I often have to cut into the brain and it is something I hate doing.’ 
 
 It is an intriguing choice, because the NHS is one of the main subject areas – Europe and the threat from Nigel Farage’s Ukip are the others – which the PM appears reluctant to dwell on. 
 
 The party’s campaign chief, Lynton Crosby, has been emphatic in his advice to Mr Cameron: if the election is dominated by the economy, you will win. 
 
 If it becomes mired in rows about Brussels, or protecting the NHS, Ed Miliband will enter Downing Street. 
 
 Mr Cameron is on a plane to cover as much ground as possible in a day, taking in marginal seats in Cornwall and Yorkshire. 
 
 Chancellor George Osborne meanwhile is campaigning against Vince Cable in Twickenham. 
 
 Focused: The Prime Minister's election campaign is firmly concentrating on the economy 
 
 Today, Mr Miliband unveils his predictable core strategy – that the NHS is not safe in Tory hands. 
 
 The Battle for Britain has begun. Cameron passionately argues that the country’s future prosperity has never been more at risk. 
 
 His message is simple and he is sticking religiously to it: if Labour get in they will wreck the economy. 
 
 ‘This is the most important Election for a generation, a real choice between continued competence or disaster. 
 
 'This is all about security from the Conservatives and the chaos you’d get from everybody else. If you lose control of your debt and deficit, you get massive cuts in things such as health and education. You get appalling insecurity, jobs lost, firms going overseas.’ 
 
 He is an extraordinarily assured politician, with a grasp of detail on everything from local planning in Cornwall to employment legislation in Yorkshire, allied to an almost messianic drive to win. 
 
 Cameron said: ‘Samantha is passionate about me continuing what I am doing. The Government has done a good job but it isn’t finished' 
 
 His confidence is particularly impressive given that he is in the fight of his political life. Even if he does defy the polls to win on May 7, Tory rebels are poised to strike –either if the margin is so slim he is forced into another Coalition with the Lib Dems, or because he campaigns to stay in Europe on terms which the Tory Right find unacceptable. 
 
 With his Old Etonian schoolfriend Boris Johnson on the brink of returning to Westminster, and growing speculation about the leadership ambitions of Mrs May, Tory MPs openly discuss the prospect of Mr Cameron stepping down halfway through the next Parliament after a victory. 
 
 According to this theory, if the 2017 referendum on our membership of the EU goes against Mr Cameron, he would be forced to resign. But if he won, he would also think it was the right time to attempt to pass the leadership mantle to Mr Osborne. 
 
 The Prime Minister says not: he is committed to serving a full, five-year second term. And if he wins in May, he will ‘hit the ground running and hit it hard’, legislating on school and welfare reforms within the first 50 days. 
 
 He says he is fully backed by his wife. ‘Samantha is passionate about me continuing what I am doing. The Government has done a good job but it isn’t finished. We have to see it through, that is her strong view.’ 
 
 Mrs Cameron, the 43-year-old ‘First Lady’, is key to understanding the Prime Minister, who next year will celebrate his 20th wedding anniversary. 
 
 When he lies awake in the middle of the night, worrying about whether to send in the special forces to rescue a hostage, she is the first person he turns to. 
 
 ‘She has very good judgment. I talk to Samantha about the most difficult decisions, life and death situations such as rescuing hostages or putting troops potentially in harm’s way. You worry a lot. It is a very turbulent night when something like that is going to happen. 
 
 ‘There is a whole process in Cobra (the emergency committee) and listening to military advice, but in the end I make the decision.’ 
 
 He adds dotingly: ‘If she’d organised Napoleon’s march on Moscow, they would have reached Vladivostok in good time. This year she did a lot of the Christmas shopping but I tried to make up for it with some cooking.’ 
 
 And the secret to their marriage? 
 
 ‘We love each other, that’s a good start. We try not to go to bed on an argument and we spend time together and don’t take it for granted.’ 
 
 The dreaded European issue will take centre stage next week when Cameron meets German Chancellor Angela Merkel in London 
 
 THE PRIME MINISTER ON... 
 
 Taking hostage-rescuing advice from Sam 'I talk to her about the most difficult decisions. There is a process in Cobra [but] she has very good judgment' Boris joining Cabinet after a victory in May 'Boris can do almost anything. I am sure there will be an opportunity... in time' His close relationship with Obama 'Yes, he sometimes calls me 'Bro' Gay weddings 'Lots of people have invited me. I’m sure I will go to one soon' 
 
 Last week saw the first gay marriages in Scotland and his legislation on the issue is something of which he is proud. 
 
 Not that he has yet attended a gay wedding. ‘Lots of people have invited me and sent me lovely letters saying if it wasn’t for you, I wouldn’t be able to marry the person I love. But I haven’t been to one yet. I’m sure I will soon.’ 
 
 So did he do it for libertarian reasons? ‘No, I’m not a libertarian. I believe in it as a man who believes in family and marriage. I don’t see why gay people who love each other shouldn’t be able to as well.’ 
 
 The dreaded European issue will take centre stage next week when Cameron meets German Chancellor Angela Merkel in London. 
 
 She has made it clear she will not countenance any prospect of heeding reformist Tory calls to rip up the European Union’s principle of freedom of movement to give the UK more power to block immigration from the rest of the EU. 
 
 The Prime Minister has pledged that if EU leaders do not give Britain more control over certain policy areas – his so-called ‘red lines’ – then he will not tell the country to back continued membership of the EU in the 2017 vote. 
 
 Merkel’s agreement is essential to his ‘red lines’ and it will be on the table for their meeting. ‘I am sure it will be part of our discussions,’ he says. 
 
 ‘The most important thing of all is being able to make changes to the welfare system. The key areas are safeguarding the single market, getting out of ever closer union, being able to veto regulations and a package of measures on welfare. 
 
 If you look at the reaction to my welfare speech in Germany and one or two European capitals, you will see they gave it a broad welcome. Germany wants Britain to stay in Europe.’ Striking a defiant note, he declares: ‘If I don’t get what is needed, I rule nothing out.’ 
 
 Is it true that up to nine members of his Cabinet want to be free to campaign for an ‘Out’ vote in the referendum? 
 
 ‘That’s news to me,’ he insists. 
 
 His relationship with Washington is less fraught. Obama rings and now calls him ‘bro’ – far better than George W Bush’s patronising ‘Yo, Blair’. 
 
 The leaders of the Right in the UK and the Left in the US found strong common ground. Like most Prime Ministers, he likes their approbation. ‘The President has said the special relationship is stronger than it has ever been privately and in public and I agree.’ 
 
 Friends: Cameron said Obama rings and now calls him ‘bro’ – far better than George W Bush’s patronising ‘Yo, Blair’ 
 
 Unveiling the Tories’ campaign poster in Halifax, Cameron is focused on the single message: It is all about the economy. He worries about Britain’s fortunes going down the drain without DIY Dave and his team there to keep everything flowing. 
 
 The big number he bandies about is the £13.5 billion in extra interest. 
 
 ‘That is the difference between the two parties in what it would cost Britain if we went with Labour’s plans. It’s like going on a spending binge with a credit card and having absolutely no idea how you are going to meet the interest. That is what Labour are about. They have learnt absolutely nothing in the past five years. It’s still more borrowing, more spending, more debt. That is totally unfair on future generations, let alone our own generation. I think its utterly irresponsible.’ 
 
 Cameron boasts of record employment and a responsible stewardship of the UK economy out of the disaster created by Labour overspending. But is he blue enough for the Tory heartland? 
 
 ‘Of course I am. I am a very instinctive Conservative. I have created a welfare system where it pays to work. I have created independent schools within the state sector bringing excellence to children wherever they are. Labour are naïve in thinking they can build a stronger country on a whole lot of debt.’ 
 
 Cameron is careful to praise Boris Johnson as his Old Etonian schoolfriend is on the brink of returning to Westminster 
 
 He is ready to roll out his plans for the first 50 days, new laws and incentives to roll back the frontiers of the state. But he will not be drawn on any specific so early in the Election race. ‘On tax cuts, we have set out our plans that you should be able to earn £12,500 before you pay any tax at all and you should be earning £50,000 before you pay the 40p rate. We couldn’t be clearer.’ 
 
 Several Ministers believe Cameron is yet to play his Election trump card, a cut or perhaps even the abolition of inheritance tax. If so, he is not showing his hand today. 
 
 ‘I want to go through the stages of people’s lives – making sure they can get a job, cutting taxes so you keep more of your own money, more school places. That might sound prosaic but to me it is what politics is about, public service.’ 
 
 He remains fundamentally opposed to the state taking more than it needs of taxpayers’ hard-earned money and he detests the idea of a wealth tax, or Mansion Tax as Labour calls it, which has so spectacularly backfired in France. 
 
 ‘That [tax] is alive and part of Ed Balls’s plan for Britain. Having a homes tax like that is wrong. Extracting money from people every year in respect of the same asset is wrong. People have worked hard all their lives and put their money in this asset. This Government has done a lot to make sure wealthy foreigners pay their taxes. 
 
 ‘But if you want to be successful you have also got to make sure your country is attractive to invest in.’ 
 
 With some simmering signs of a potential leadership fight within the Tory ranks after the Election, Cameron is lightly dismissive. 
 
 He is careful to praise Boris Johnson and Theresa May, but reveals that he authorised the removal last month of May’s close aide Nick Timothy from the list of Tory candidates at the next Election for not campaigning for the party in the Rochester by-election. If selected, Mr Timothy would have been in prime position to run a May leadership bid. 
 
 The fact about Boris is he can do almost anything, as I have discovered. What happens to him after the Election will have to be discussed 
 
 ‘We had to apply a rule fairly that everyone on a candidates list has to canvass in a by-election.’ Was he consulted about Mr Timothy’s removal? ‘I am consulted about everything.’ 
 
 And he makes no promise of an early Cabinet seat for the London Mayor. ‘The fact about Boris is he can do almost anything, as I have discovered. What happens to him after the Election will have to be discussed. He has an enormous talent. 
 
 ‘I’m delighted he is coming back to the House. I hope I played a role in helping him do that. He is an absolute star. He wants to focus on being Mayor because he will be an MP and Mayor but I am sure in time there will be an opportunity for him to serve in other ways.’ 
 
 This Election is the first where social media will play a crucial role. On Friday, Cameron was asked to do more than a dozen selfies in as many minutes. 
 
 ‘The danger is everything becomes an obsession for five minutes, rather than getting to the heart of the issues,’ says the man who famously posed for one at Nelson Mandela’s funeral. 
 
 Actually, he often grabs the cameras to expedite the selfie process and knows it is the best way to get his presence out beyond the traditional campaign trail. 
 
 But it is the deficit and the spectre of Labour as debt gorgers to which he keeps returning for lasting effect. ||||| Barack Obama is so close to David Cameron that the US President calls him "bro", the Prime Minister has revealed. 
 
 Speaking to The Mail on Sunday, Mr Cameron described the famously “special�? relationship between Washington and Westminster as “stronger than it has ever been, privately and in public,�? and that during phone calls Obama refers to him as “bro�?. 
 
 For those less well-versed in youth vernacular, the Urban Dictionary helpfully defines the term as describing “an alpha male idiot�? or “obnoxious partying males often seen at college parties�?. 
 
 “Bro�? may also describe a type of bra designed specifically for men. 
 
 However, perhaps it should be assumed Obama uses it as a term of endearment, to mean close pals or “brothers�?. 
 
 Either way, it can be seen as a step forward from George W Bush’s condescending idiom: “Yo, Blair.�? 
 
 As if we needed any more proof of the blossoming bromance, here are some pictures of the transatlantic “bros�? looking all buddied-up.
– The "special relationship" between the US and the UK is still back-slappingly good, according to David Cameron. President Obama has said "the special relationship is stronger than it has ever been privately and in public and I agree," the British prime minister tells the Daily Mail, revealing that Obama sometimes calls him "bro" when they talk on the phone. The term is more commonly associated with frat boys than world leaders, but the Independent has decided it's still "a step forward" from George W. Bush's "condescending" greeting for Tony Blair: "Yo, Blair!" In the Mail interview, Cameron, who faces a tough election battle in May, also discusses gay marriage—he's proud of introducing the legislation and says he will probably attend a same-sex wedding soon—and his own marriage. He says Samantha Cameron is the first person he turns to for advice on difficult decisions like sending in special forces to rescue hostages. "If she'd organized Napoleon’s march on Moscow, they would have reached Vladivostok in good time," he says.