U.K. Chancellor George Osborne | Matthew Horwood/WPA Pool via Getty images Letter from London The most powerful man in Britain That’s George Osborne, not David Cameron.

LONDON — Twenty-four hours after George Osborne delivered the first completely Tory budget since 1996, a very funny thing happened. Senior party sources close to David Cameron, the British Prime Minister, made their customary Friday phone call to editors as they put together the weekend papers. This usually furnishes No. 10 officials with the chance to place a couple of stories, bend a few news lines, flatter commentators and settle scores.

This week, however, the tone was rather different; surprising, even, given the budget was widely hailed a success. Instead of the usual spiel, Cameron's cronies went in for some special pleading. They insisted that the PM was involved in the budget process, rather than a mere bystander; that he is still the ultimate author of the government's strategy — and, therefore, that plaudits deserved to go to him, too. It wasn't all down to the Chancellor of the Exchequer, they insisted.

It has long been said that Cameron is the face of the Osborne government. So dominant is the latter, and so gripped are the Tories by the economic narrative that Osborne has scripted, that the political philosophy we call conservatism looks — in its modern British version — like a branch of Osbornomics. One popular variant on this theme is the idea that Cameron is a self-styled Chairman, while Osborne is a hands-on Chief Executive. Not for the PM the grubby detail of policy, handling crises and managing personnel: If you want a decision made, or a problem solved, or an ally rescued, it's George you go to see, not David.

But it's got to the stage where some of those close to Cameron really are having to insist he's still involved. This is a remarkable state of affairs: Despite being the first Tory majority leader for two decades, Cameron is in danger of becoming eclipsed in his own party. If such a claim has always threatened to be true, it acquired much more plausibility when, during the election campaign, he announced that he would stand down after serving a second term.

Subsequently justified as a “straight answer to a straight question,” Cameron's personal adoption of the 22nd Amendment — which limits presidents to two terms — had the same effect here as it has in America. It sapped the leader of authority, and by placing a limit of his occupancy of the top job, re-orientated his party around the presumed successor. Had the Tories failed again to win a majority in May, that label would have transferred to Boris Johnson. Cameron and Osborne have been so closely aligned that a verdict on one is taken as a verdict on the other.

Cameron is in danger of becoming eclipsed in his own party.

But the Tory victory was seen ultimately as vindication of the party's economic strategy (as well as fear of Ed Miliband and the SNP, of course). That put Osborne in pole position, whereas Boris, resigned to the backbenches and unable to steer the ship of government, is subdued. No wonder Sunday papers have splashed recently with stories about allies of the London Mayor saying he has been insulted by Osborne and Theresa May, the Home Secretary and his other top rival for No. 10. There's a major briefing operation going on against Boris at the moment, and the feeling is that it's been sanctioned by Osborne.

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It must never be forgotten that Cameron was a highly effective PR long before he was a highly effective PM. An enemy of ideology, his sensibility is that of the pragmatist and ambassador, a presentable front man for a nation that, in Dean Acheson's still-apt formulation, lost an empire but is yet to find a role.

The same is not true of Osborne. He studied Modern History at Oxford, not Politics, Philosophy & Economics (PPE), and has a historian's sensibility. Though adept — much too adept, his critics point out — at the daily machinations of politics, he grasps that voters don't think about politics on a daily basis, but rather in terms of images and periods of several years. If we are living in something like the Age of Osborne, it is because he grasps these truths more deeply than any of his contemporaries — and happens to be in a position of strength to do something about them.

Think, for instance, of the most powerful metaphors and phrases that abound in British politics in our time. To Westminster-watchers, these are boring cliches; to the voters, they are subliminal messages that deliver majority government. “Long-term economic plan” is a deeply uninspiring phrase; but having been road-tested to death with focus groups, it tended to crop up around half a dozen times when Osborne went on BBC Radio 4's Today program before the election.

Then there are the metaphors. The idea that Labour didn't “fix the roof while the sun was shining” is pure Osborne. It infuriates the Labour party, and has graduated from tedious formulation to effective put-down: In recent Budgets, Osborne has argue that by contrast the Tory party did fix the roof. The same goes for the idea that voters shouldn't give the keys (i.e. power) back to the people who crashed the car (i.e. Labour). Watch out for this if Andy Burnham, a former Chief Secretary to the Treasury, becomes Labour leader.

Finally, there was Red Ed, the hugely effective label for Ed Miliband. Obviously this had the ring of truth about it, because Miliband was well to the left of Tony Blair, and indeed his brother David. But in terms of brutal politics, Osborne, who came up with the phrase, has to be credited for making it stick during Labour's last unedifying leadership battle.

“Tell him what to write George!” — Peter Mandelson

He did so largely with the help of the Daily Mail, and this is another vital component of Osborne's rise to pre-eminence. If Cameron were a newspaper, he'd be The Daily Telegraph, whereas if Osborne were one, he'd be The Economist. As a social and economic liberal, he is not completely in sync with Britain's right-wing press. But he has manipulated allies in the media by investing huge amounts of time in them. Just as backbench Tories prefer Osborne to Cameron because he works harder, so journalists have tended to prefer Osborne to Cameron because he gives them more time. Osborne spends plenty of time talking to editors (full disclosure: that includes me — we had an hour together at No. 11 some months ago).

When Hannah Rothshchild made a film about Labour politician Peter Mandelson around the 2010 election, there was an extraordinary scene after one of the television debates when Osborne was leaning over the desk and computer of Benedict Brogan, then Deputy Editor of the Daily Mail. “Tell him what to write George!” bellowed Mandelson after eyeing this rendez-vous, with Douglas Alexander, the former Labour MP and Shadow Foreign Secretary, sniggering with scorn. Paul Dacre, the editor of the Daily Mail and the most powerful print journalist in Britain, is not a fan of Cameron's, but has generally given Osbornomics his endorsement.

So key is the Daily Mail to British life, and therefore to Osborne's prospects, that the Chancellor recently hired James Chapman, the paper's Political Editor, to be his chief spin doctor. This paid some early dividends when, after the budget, the Mail splashed with a heroic picture of Osborne next to the headline: “Fearless George slays the dragons.” High praise indeed.

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Sometimes Osborne's fondness for headlines and laying political traps causes him to overreach. In the budget this March, he announced funding of £1 million to commemorate the 600th anniversary of the Battle of Agincourt. This allowed him to come up with a gag that delighted the Tory benches: "The Battle of Agincourt is, of course, celebrated by Shakespeare as a victory secured by a band of brothers. [A sly reference to Ed Miliband's taking on his brother David here.] It is also when a strong leader defeated an ill-judged alliance between the champion of a united Europe and a renegade force of Scottish nationalists." I'm told that Treasury officials had a very low opinion of Osborne spending taxpayers money to fund a shoddy, partisan joke.

Hiring has been a vital weapon in the armory of the Chancellor. Lynton Crosby, who ran the Tory campaign, was an Osborne recruit. The Chancellor has used the power of patronage to give key jobs to allies, and keep rivals at bay. Whenever Cabinet reshuffles are announced these days, the only prism through which they are seen is Osborne's strengthened grip on power. Look at the top of the Tory party and you see close former colleagues of his everywhere. Philip Hammond, the Foreign Secretary, was his underling at the Treasury as Chief Secretary. Sajid Javid, the Business Secretary, is very much in the Osborne camp. He, Amber Rudd, Greg Hands and Matthew Hancock — all senior figures in Cabinet — are former Principal Private Secretaries to him. This ruthless exploitation of the levers of power gives him advantages his major rivals would dearly love, and desperately lack.

Like Cameron, Osborne was conditioned by the Tories’ long years in Opposition, when the two worked as special advisers. For them, the dominant figure in politics was not Margaret Thatcher (still the ultimate heroine of the Tory Right) but Tony Blair. It was Blair who commanded power, and reshaped British politics in his own image. That is why, once in No. 10, both Cameron and Osborne have modeled themselves on Blair, frequently calling on the former PM and his acolytes for advice.

The Conservative-Liberal Democrat Coalition was essentially New Labour minus the spare change, carrying on the reformist agenda of Blair on schools, welfare and other public services. Now unshackled from coalition, they are continuing largely along that path, and winning Blairite admirers along the way. To that end, I asked Peter Mandelson what made Osborne such an effective politician. He told me: "Osborne has reached his pre-eminence because he has a rare combination in politics: strategic sense, policy depth, message discipline, keen intuition and personal humor."

Osborne is unbound, free to shape the contours of public life in Britain.

And what, I asked, does he have to do to make it to the very top? Mandelson said: "To make it to No. 10 he has to do two things: continue to show his party he is an electoral winner and communicate more warmth to the public. A little more light and shade, a bit of pastel color, would not go amiss. He needs to show he can relax without, of course, loosening his grip for a second."

It is sometimes forgotten that Osborne was invited by Michael Howard, then outgoing Tory leader, to run as Tory leader in 2005. Then just 33, he had the self-awareness to realize it was too soon, and that his close friend Cameron was the better-placed man. At that point, he made a decision to stay in politics for perhaps a decade longer than Cameron. For him it would be a marathon, not a sprint. He and Cameron have had a common aim and a common enemy: first Gordon Brown and Labour; then the Lib Dems who constrained them in Coalition. Now those enemies are gone: Labour are in disarray and the Lib Dems vanquished. As such, Osborne is unbound, free to shape the contours of public life in Britain, and conscious that his boss, Cameron, will soon be distracted by European negotiations.

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In modern British history, the best Chancellors have been distinguished by two characteristics: First, they have wanted to save, whereas Prime Ministers have wanted to spend; and second, they have tended to be at odds with No. 10, partly for that reason. Roy Jenkins, Denis Healey, Geoffrey Howe and Ken Clarke all fell into this category.

The curiosity of Osborne's current position is that he isn't so much at odds with No. 10 as giving it instruction; and whereas he spent his first Parliament as Chancellor saving through austerity, he is now spending happily. That is why he used the budget to slow the pace of deficit reduction, and committed to lavish expenditure like using 2 percent of GDP for defense. In other words, Osborne doesn't fit readily into the tradition of celebrated Chancellors, because he is effectively more than a Chancellor — a Prime Minister in all but name.

With the clock ticking on Cameron's premiership, the real question may be not whether Osborne will ever become Prime Minister to rule from No. 10 Downing Street, but rather whether there's much point getting the removal men in, given he already rules the country from No. 11. Vanity, and sheer egoism, will probably kick in at some point. Until then, Cameron's people will continue briefing journalists to insist the Prime Minister is very much involved in running the country, rather than a bystander in his Chancellor's game.

Amol Rajan is editor of the Independent of London.

This article has been updated to remove Matthew Hancock from the list of former Principal Private Secretaries.