Sketch: After years of misery, Osborne overdoes the gloating

George Osborne's parents watched their little boy be all "serious" at the Conservative party conference – but he couldn't help showing off to them all the same.

The chancellor ended September 2013 as he began it: succumbing to the overwhelming political urge to gloat. The fact his mother and father were present to watch him do so probably didn't help.

Just as in his speech at a London construction site, the chancellor fought hard against the temptations of a premature victory lap. "It is not even close to being over," he insisted in his most firmly 'I'm not gloating' moment. His tagline – "a serious plan for a grown-up country" – was remarkably unsexy even in a trade not exactly renowned for its good looks.

This was the unappetising meat in a sandwich of self-congratulation, however. At the beginning and the end the tone was one of exultation and delight.

After being introduced by Karren Brady as "the only man I'd be an apprentice for" Osborne did not hang around. "Our plan is working," he declared right at the start. The euphoria may have been a little overdone. It felt like an Oscar acceptance speech, thanking the British public for sticking with austerity. "We held out nerve. Britain is turning a corner," he declared.

The implicit assumption was that the UK is 100% on the side of the Tory spending cutters, which showed just how much of an impact yesterday's TUC protest here in Manchester made inside the secure zone. Labour, which takes a different line on the economy which at least one or two voters might agree with at the next general election, was dismissed outright.

Osborne does not need much encouragement to get all ideological on the opposition. So he pounced at Ed Miliband's price freeze promise in Brighton last week, linking it to the arguments of Marx and Das Kapital. It looked for a moment as if he was about to mention a Fifth Column, too, but it didn't come to that.

Despite three weeks of appalling political jokes, the chancellor seemed convinced that he could do better than anyone else, too. He began poorly, with an excruciatingly awful gag about Nick Clegg and Vince Cable. But then the quality improved. He said the Tories' initial suspicion about Ed Miliband that the lights are on but nobody's home turned out to be "half right". Ed and his brother David were "the biggest sibling rivalry since the Bible: Cain and not very Abel". The Tories loved that. Haw haw haw!

There was policy here, too: a new ambition to achieve a budget surplus by 2020, presumably extending austerity unnecessarily but doing so "as insurance against difficult times ahead". The fuel duty freeze is to be extended until the 2015 general election, too. One is more likely to be popular with the voters than the other.

Osborne has had a tough ride in the last two years. His political capital has fallen as a result of the 2012 omnishambles Budget and many still believe William Hague is the more plausible 'under a truck' alternative to David Cameron. Now the economy is recovering the chancellor's own political capital is rising. The prime minister, watching from somewhere in the fifth row, will have approved entirely – if not quite as much as Osborne's parents.

They were watching their little boy be all "grown-up". For a time it looked like the chancellor's initial burst of gloating might have been it. But then came a conclusion so dripping with overblown rhetoric they should have handed out waterproofs to delegates on the way in.

Try pausing in the middle of a sentence, breathing out through your nose and looking from side to side. You might look like a constipated frog. But when George Osborne does it, the result is a paragon of self-satisfaction.

This is how his speech ended. "For the sun has started to rise above the hill. And the future looks brighter than it did, just a few dark years ago," the chancellor finished. This sort of language is acceptable when you are writing The Lord Of The Rings but not in any other context. It was so overdone even a steak knife wouldn't be enough to hack through it.

Osborne, deprived of any good news for several years, couldn't help himself. He was handed perhaps the worst hand of any incoming chancellor since the War and has spent his last five conference speeches painting pictures in various shades of grey. This year was different: a chance for the chancellor to let himself go. He splashed the colours around with abandon – and made an awful mess in the process.