A detergent auxiliary composition comprising from 0.001 wt % to 99 wt % cleaning polymer having a hydrophilic backbone and at least one hydrophobic pendant group, and an adjunct ingredient in which the hydrophilic backbone constitutes less than 50%, preferably less than 45% by weight of the polymer. The detergent auxiliary composition may be, for example a spray-dried particle or an agglomerate. Also described are detergent compositions comprising the detergent auxiliary composition.