The Chancellor claims there is now "real momentum" in the UK's economic recovery after GDP growth of 0.8% was measured in the third quarter.
The Office for National Statistics (ONS) said it marked the strongest period of growth in more than three years - with services, construction and manufacturing all expanding.
It was also the third successive period of improving output, in line with the expectations of economists, though some had forecast growth to have reached 1%.
The ONS said construction - a sector bolstered by Government initiatives such as Help to Buy - surged by 2.5%.
George Osborne said: "This shows that Britain's hard work is paying off & the country is on the path to prosperity."

Prime Minister David Cameron tweeted: "Today's encouraging #GDP growth figures are another sign we are turning a corner."
Labour argued the growth was "long overdue".
Overall GDP was 1.5% ahead of the same period last year - a time when the economy was being boosted by the Olympics and Paralympics.
But the economy remains 2.5% off its pre-recession peak at the start of 2008.

During the third quarter, construction was boosted by new work on private housing and private commercial building as well as domestic home repair and maintenance but remained 12.5% off its 2008 high.
Housebuilders have been buoyed by the Government's Help to Buy scheme, which recently launched a new phase offering mortgage guarantees.
Production grew by 0.5%, though this remains 12.8% off its 2008 level, while within this manufacturing improved 0.9% in the third quarter.
The powerhouse services sector, which represents three-quarters of economic output, grew by 0.7% and is now 0.6% above its pre-crisis peak.
The largest contributions here came from business services and finance, followed by distribution, hotels and restaurants.
But the wider statistics highlighted one piece of bad news - in terms of UK growth.
The contribution from utilities - including gas and electricity - tumbled by 6.8% in the period, possibly a result of the warm summer compared to the same period last year which was largely a washout and cool.
The figure was seen as a potential factor behind the decision among energy suppliers to increase household bills - to make up for lower demand.
Chris Williamson, chief economist at Markit, said: "Britain is booming again with the economy showing the most sustainable and robust-looking upturn since the financial crisis."
But Alan Clarke of Scotiabank said the figure was a "tad disappointing" - given survey data indicating growth nearer 1% - and "wasn't a home run".
Shadow chancellor Ed Balls said: "After three damaging years of flatlining, it's both welcome and long overdue that our economy is growing again.

"But for millions of people across the country still seeing prices rising faster than their wages this is no recovery at all."
Dave Prentis, general secretary of the Unison union, said growth figures will "mean nothing to the vast majority of people in this country faced with mounting household bills and stagnant wages."
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