LONDON, July 30 - British retail sales growth rose in July at the fastest rate since April 2002, helped by warm weather and an interest rate cut at the start of the month, the Confederation of British Industry said on Wednesday. The CBI's latest monthly survey of the retail sector showed 54 percent of firms said sales were up compared with the same month last year while 27 percent said sales were down, giving a balance of +27 percent compared with +10 percent in June. Retailers had expected a balance of +10 percent. Retailers expectations of growth over August also jumped to the highest level since December 2002 at +24. "Retailers have had a surprisingly good July," said Doug Godden, the CBI's head of economic analysis. "Warm weather and the later start to the summer sales have particularly helped sales of food and drink and electrical goods. The latest cut in interest rates may also have helped, and more generally, consumer confidence appears to be holding up well." The CBI's figures back up the picture painted by official data. According to the Office of National Statistics, retail sales surged in June as the heatwave prompted shoppers rushed to buy summer goods. The 1.9 percent rise month on month was the sharpest in 1-1/2 years. The strong figures will damp hopes for further interest rate cuts. The CBI said interest rates were currently at the correct level but that the Bank of England needs to be vigilant and that if global demand does not pick up there may be a need for further cuts later in the year. The Bank of England cut interest rates to a 48-year low of 3.5 percent at the beginning of July.