London: British department store operator Debenhams Plc slashed its annual profit forecast on Thursday after it was forced to cut prices to drive Christmas gift sales, hammering its shares and putting the stock on track for its worst ever daily fall. The downturn at the 240-year-old group illustrates the struggle traditional British retailers face against online competition, a decline in demand for clothing and pressure on consumer spending. Debenhams said its underlying British sales fell 2.6 per cent in the 17 weeks to December 30, reflecting a “volatile and competitive market” in the months before Christmas and a disappointing first week of its sale after Dec. 25. Shares fell 20 per cent and weighed on fellow retailers such as Marks & Spencer, just a day after an upbeat statement from Next raised hopes that retailers had defied forecasts for gloomy Christmas trading.