§ Mr. Andrew Turner
To ask the Chancellor of the Exchequer with which currencies sterling has maintained greatest exchange rate stability since 1997; and how that is measured. 
§ Ruth Kelly
There is no unique measure of exchange rate stability. One possible measure is the co-efficient of variation. Since the start of 1997, of the currencies comprising sterling ERI, the Swiss franc-sterling exchange rate has had the lowest co-efficient of variation.