Abstract: An aqueous biocidal composition comprising: (a) a compound of formula (II): or a derivative salt thereof wherein L is a linking group; each of R1, R2 and R3 is independently selected from an optionally substituted alkyl, alkenyl, aryl or alkoxy group; R4 is oxygen or an optionally substituted alkyl, alkenyl or aryl group; each of R5 and R6 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.