To describe George Osborne's conference speech as light on laughs would tend, to put it kindly, towards understatement. I haven't been so unamused by any experience, in fact, since the invasive swab administered by a sadistic Glaswegian nurse in the Charing Cross hospital's genito-urinary department days before the last Tory general election win in 1992 (clean bill of health, thanks for wondering). Even so, Mr Osborne's address did bring to mind a good and time-honoured gag.

It's the one applied to every outlandishly charmless public figure, including, just occasionally, Lord Lloyd-Webber, who morosely asks a theatrical friend why everyone takes an instant dislike to him. "Because, Andrew," replies the friend, "it saves time."

Mr Osborne also has a face that might have been designed by the CGI boys at Pixar to elicit dislike, and the public persona to match. That snap of him sneering into the distance like a foppish Flashman in his Bullingdon tails captures a sense of born-to-govern superiority and a dash of casual cruelty that the decades have done little to dissipate. He still looks like a cocky, disdainful git, to be blunt, and his manner underscores the gut reaction.

All in all, then, the tone he struck in Manchester was a personal masterstroke. If you know you're going to be universally despised the moment you enter No 11, why not save time? That way no one is liable to be disappointed. They might even melt a little should you prove a touch less loathsome than anticipated.

What goes for the personal goes, to the nth degree, for the political. The received wisdom about all his sombre talk of public sector pay freezes, an extra year at work, withdrawal of means-tested benefits and the rest is that so direct a challenge to middle income self-interest constitutes a "colossal political gamble". I'm not convinced this is right. Sometimes playing safe is the really reckless gamble, as Gordon Brown might privately agree about his fretful failure to call an election two years ago. This may be just such a case.

Had Mr Osborne contented himself with nebulous cobblers about cutting billions solely through "greater efficiency", he'd have taken the real gamble of seeming as feebly marooned on fantasy island as Labour portrayed itself in Brighton. Instead he spelt out the full horror ahead, or rather pretended to. In fact the savings will come to about £7bn per annum over a full five-year term ... not so much peanuts to a trillion-pound economy as the salty flakes the peanuts leave on your fingers.

By impersonating Stafford Cripps during one of his colitis attacks, and exaggerating the brutal austerity, his intent was not to sugar the pill but to sour it. Clearly he judges that the safe bet is to trust the public's mature realism about the pickle we're in, whereas the crazy throw of the dice would have been to ape Gordon by glancing up at the rainclouds and slapping on the Ambre Solaire.

How the opinion polls will react in the short term we will soon see, and one imagines that David Cameron will play good cop today to mitigate the impact by balancing the doominess with an Obamaniacal schtick about change, hope and renewal. But the crucial, tonal effect of Mr Osborne's speech has been to create something novel in British politics, if not unique. The opposition now acts like a government in cleaving to harsh specifics, while by continuing to soft-soap us with frothy generalities the government behaves like an unusually feckless opposition.

Thus has Mr Obsorne done much to slay one of the two remaining dragons with the firepower to prevent the Conservatives winning a workable majority. Despite the presence of William Hague and Kenneth Clarke, there was still a whiff off the ingénue about these Tories. That was largely deodorised on Tuesday, and I suspect that the public like being treated as grown-ups enough to reward this faux bravery next May.

The other dragon, of course, is the class thing that runs too deep for this George to slay with "We're all in this together". It's a cuddly mantra, and no doubt it went down a storm with the focus groups. Yet from a member of the Anglo-Irish aristocracy, heir to a 17th baronet, it rings hollow. If we are all in this together, most of us are sat on the floor without the cushions of present wealth and a future wallpaper inheritance to keep the splinters from our bums.

So a vital factor for the Tories is that George's father survives until May. It is one thing to have telly dramas satirising the Bullingdonian Boris and Dave, and inverse snobbery remains a powerful force (although it is no less patently absurd to despise posh chaps for their 19-year-old selves than to write off middle-aged men from rough council estates for a spot of adolescent joy-riding).

But Labour yields to wishful thinking if it imagines that old Etonian history will do it much good at the polls, not least because the Tories have a simple rebuttal. To the charge of privileged youth, they need only mention Mr Tony Blair and his puritan wife Cherie recently paid over a million in cash to install their son Nicky in a Chelsea mews.

If, however, Mr Osborne were to become Sir George and inherit untold millions before the election, this would bring the class debate into the present and turn "we're all in this together" into an effective boomerang. It may even have crossed No 10's mind to take out a contract on Sir Peter, although with Damian McBride off the team one assumes this will remain a pipedream.

The still Mr Osborne, a smart operator for several years, is now a battle-hardened one as well. He somehow rode the Mandelson sucker-punch over the yachtocracy of Corfu, and is the stronger for it. Adorable he will never be, and as an orator he makes the Speaking Clock sound like Cicero, but undeniably he is extremely clever. By portraying himself as a murderous financial hard man (a kind of Sir Stafford Crippen), he has pulled off that cutest of political tricks by transforming a weakness into a strength.

Labour has underestimated George Osborne, and the party may shortly pay the price.