George Osborne is not a natural actor. For all the 5:2 makeover, the Caesar haircut and slimline profile, his voice is still reedy, prone to cracking mid-performance – and, more important, he can never quite hide his inner self. The stage directions may say benign and caring, but in repose his face turns unbidden into that default snarl.

Yet on Wednesday the chancellor did quite the acting job. He projected confidence and command: the man in charge, turning the economy around, lifting his country off its knees so that “Britain is walking tall again”.

In his telling, in 2010 he inherited a place in ruins, a kingdom reduced to rubble where the skies were permanently grey. Now, thanks to him and his steadfast pursuit of toughbut necessary action, at last “the sun is starting to shine”. He acted as if his opponents were the merest mice, to be crushed under foot or dismissed with a joke. And yet, acting this was. Because, for all its bravado and swagger, this was the speech of a man – and a party – on the defensive.

Again and again, Osborne made a promise or offered a boast designed to blunt a Labour sword or parry a Labour attack. Decode the motive behind almost every paragraph and you’d have a complete set of either Labour attack lines or negative perceptions of the Conservative party that refuse to go away.

Take the chancellor’s hope of getting the economy into the black in the next parliament, so that by 2019-20 the country will have a surplus of £7bn. That was a massive climbdown from the figure Osborne aspired to just three months ago, when he delivered his autumn statement. Back then, Osborne wanted to close out the next term with a surplus of £23bn, a figure that could be achieved by only the most drastic cuts in public spending.

So why the sudden shrinking of ambition? The clue came when Osborne boasted: “For those interested in the history of these things, that will mean state spending as a share of our national income the same size as Britain had in the year 2000.”

Ah, so that’s the reason. In December, Osborne was stung by the verdict of the Office for Budget Responsibility that his plans would see state spending, as a percentage of GDP, reduced to levels not seen since the 1930s. The BBC conjured up Orwellian images of The Road to Wigan Pier. Labour found that the line cut through.

So Osborne moved to block it, altering his fiscal plans so that he could replace the toxic “1930s” with the much less threatening prospect of a return to 2000 – a year associated with New Labour in its pomp. (Never mind that, at that point, the Blair government had been on a two-year spending diet, sticking to stingy limits set by the previous Tory administration, limits that had driven the NHS to the point of collapse.)

Or consider what is the Tory brand’s greatest defect: the perception that they are the party of the rich. Ed Miliband, in his spirited reply, reminded them of it, attacking “the trust fund chancellor and the Bullingdon Club prime minister”.

Osborne moved to block that too, channelling his inner Occupy activist as he bragged about the way he was sticking it to the “1%”. He boasted that soon that gilded group would be paying 27% of all income tax, a share larger than it ever was under the last Labour government.

In that same spirit, and as if to exorcise the memory of the calamitous omnishambles budget of 2012 – when the most memorable giveaway was to top earners paying the then 50p tax rate – he sought to shower his largesse on those lower down the food chain.

Middle Britain is the intended beneficiary of his change to the point at which the 40% tax rate kicks in. The well-off middle class are also the people likeliest to do well out of his right-to-buy Isa scheme, which will see those with a spare £24,000 handed £6,000 of public money to put away for the day their children want to buy their own home. Still, that can be sold as a gift for the aspirational many rather than a present for the very richest few.

For much of the life of this coalition government, its weakest spot was the decline in living standards. There was a time Labour’s two Eds thought that failure alone might see them to victory.

So Osborne reached for the stats that might allow him to defuse that Labour bomb once and for all. Recalling the lethal power of Ronald Reagan’s question to voters in 1980 – “Are you better off now than you were four years ago?” – the chancellor alighted on the metrics that suited him and declared: “To the question of whether people are better off at the end of this parliament than they were five years ago we can give the resounding answer ‘yes’.”

But surely the Tories are the party of the City and the south-east, metropolitan elite to their fingertips? Osborne wanted to rub out that attack line too. This time he didn’t just bang on about his cherished “northern powerhouse”, but promised help for Scotland’s oil industry and for transport links in the English south-west. There were shout-outs for Yorkshire, Wales, the Midlands, Cambridge and beyond, each place depicted as humming with activity thanks to generous George.

It continued in that vein throughout. Anyone who thought a government that had appointed HSBC’s Stephen Green as a trade minister was soft on tax evasion should think again: new criminal sanctions were coming on those not paying their fair share.

All of this was delivered with vim, but there was no hiding that it was the work of a man on the defensive. And there will be more defending to do. Osborne, who mocked Miliband for forgetting to mention the deficit in his party conference speech, said next to nothing about NHS spending. And the OBR has already woundingly described his plans for the next parliament – in which sharp cuts in spending are to be followed by steep increases – as a “rollercoaster”.

Still, there was an even larger act of performance Osborne had to pull off. Not only did he have to disguise defence as attack, he also had to dress up failure as success. Remember that Osborne promised to present this final pre-election budget having erased his favoured measure of the deficit. Instead, he is halfway through at best. And the deficit still stands at £90bn.

But Labour has never quite found the right way of saying that. So Osborne has been allowed to U-turn, to retreat in the face of failure – yet cast it all as a triumph so his party can campaign on that age-old message: we’re on the right track, don’t turn back. He’ll be hoping that that’s just enough to keep the Osborne show on stage a few years longer.