The Office for National Statistics said gross domestic product rose 0.1% in August, following 0.4% growth in July and confounding a forecast by City economists of a 0.1% contraction.
The reading arrives with the Middle East conflict rattling the global economy and hitting British households and businesses with a surge in energy costs. The consumer-facing services sector fell 0.3% on the month, after a 0.1% decline in July, with the largest negative contribution coming from sports, amusement and recreation activities and a slump in food and drink services. Analysts said the fall could signal a reversal of an earlier boost from the World Cup and unusually hot weather, or reflect households trimming their spending.
Despite no growth in the overall services sector, the surprise improvement was driven by strength in manufacturing, with 0.8% growth in the wider production sector, which includes manufacturing, mining and energy generation. Construction output fell 0.2%.
Sanjay Raja, chief UK economist at Deutsche Bank, said: "Undoubtedly, there may be some hiccups to come in the run up to year end, especially as energy prices continue to bite household incomes, and higher rates continue to drag on spending and investment. The good news? The UK's resilience story continues. It's hard to overstate how strong the UK performance has been all year."
Britain's economy has shown more resilience than expected since the start of the Iran war, recording the strongest rate of growth in the G7 in the first half of 2026. Official figures suggested a strong expansion in AI-related business activity was one factor behind the surprise rise. Jake Finney, senior economist at PwC, said: "The UK's growth performance has been a bright spot amid a less impressive run of economic news following events in the Middle East. Business investment has been an important driver, particularly spending on ICT hardware, likely linked to the build-out of AI infrastructure."
The International Monetary Fund this week upgraded its UK growth forecasts for this year, but warned it expected a modest slowdown in 2027 as higher energy prices take their toll.
Healey is under pressure to use his tax and spending address to the Commons on 28 October to announce a package of support to soften the blow, including energy help for poorer households, while facing a delicate balancing act amid a sharp increase in government borrowing costs.