British industrial output fell more sharply than expected in September, reinforcing fears an incipient recovery will struggle to gather pace.
Excluding a decline in June, due partly to an extra public holiday, the 1.7% monthly fall was the biggest since August 2009 and much bigger than the 0.6% decline analysts had forecast.
The data further complicates the economic picture for policymakers.
Economists have been paring back expectations of more monetary stimulus in November since a surprise 1% rise in UK output between July and September.
Many economists pointed out that the main driver of the industrial data weakness was a slump in oil and gas production, which was due to maintenance work on North Sea platforms.
However, manufacturing output rose by a smaller than expected 0.1% in September on the month after a downwardly revised drop of 1.2%in August, the Office for National Statistics said.
The downbeat data come two days before the Bank of England must decide whether to inject further cash into the economy to prop up the recovery. The bank has already bought government bonds worth £375 billion sterling in its quantitative easing programme and several central bankers have made cautious comments.
Britain's return to growth is at threat from public spending cuts, tax rises and low wage growth that have sapped consumer confidence, while the euro zone debt crisis has cast a dark cloud over the business outlook.
Business surveys have indicated a weak start to the final quarter of the year and economists have pointed out that one-off factors contributed to Britain's third quarter growth.
A survey showed today that business in the dominant services sector expanded at the slowest pace in almost two years in October and optimism about the outlook dimmed.
Other news on the economy today painted a mixed picture. British retail sales slowed sharply in October and house prices fell at a faster rate. However, new car sales rose strongly and the car business lobby SMMT raised its forecast for sales this year.
Industrial production was 0.9% higher in the three months that ended in September compared to the previous three-month period. It was unchanged in the three months to August. Mining and quarrying recorded the biggest monthly drop since February 1974, while oil and gas extraction posted the largest fall since records began in 1997.
