Economist polled by Reuters had anticipated a fall of 0.1 percent on the month and a gain of 2.8 percent on the year, compared to the 2.7 percent recorded.
The ONS said the amount spent in the retail industry slipped by 0.6 percent compared to August, with feedback from retailers putting the dip in sales down to the warm weather, meaning shoppers delayed purchases of autumn and winter clothing and footwear.
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Average store prices, including fuel fell by 1.4 percent over the period, when compared to September last year, marking the largest fall since July 2009, with the largest contribution to this fall coming from petrol stations, which fell over 5 percent.
A joint report from the British Retail Consortium (BRC) and KPMG last week said U.K. retail sales fell to their lowest levels last month since December 2008 as clothing and footwear sales hit record lows.
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