asked the Secretary of State for Prices and Consumer Protection what were the highest and lowest prices that were being charged in October 1977 for four-star petrol as recorded by his Department; and if he will make a statement on the way in which his Department monitors such prices.

My Department does not monitor retail petrol prices directly. The Department of Energy collects some information on the retail price of petrol but not in the form requested, as it relates to average prices reported by a number of oil companies and not each company's full range. A report published by the Price Commission in 1975 (Motor Fuel Retailers' Margin's Final Report) sets out reasons for the variation in prices.