An aqueous biocidal composition comprising: (a) a compound of formula (II): or a derivative salt thereof wherein L is a linking group each of R, Rand Ris independently selected from an optionally substituted alkyl, alkenyl, aryl or alkoxy group R is oxygen or an optionally substituted alkyl, alkenyl or aryl group each of R and R is an optionally substituted alkyl, alkenyl or aryl group and n is 0 or 1 (b) a hydrocarbyl saccharide compound and (c) at least one cationic biocide wherein the molar ratio of component (b) to component (a) is at least 0.5:1.
