A liquid laundry detergent formulation is provided, comprising: a liquid carrier; a cleaning surfactant; and a cleaning booster polymer, wherein the cleaning booster polymer has structural units of a monoethylenically unsaturated carboxylic acid monomer; structural units of an ethylenically unsaturated monomer of formula (I)




and,



optionally, structural units of an ethylenically unsaturated monomer of formula (II)










wherein x is an average of 0 to 20; wherein y is an average of 0 to 30; wherein x+y>1;
wherein R1 is a —C1-4 alkyl group; and wherein R2 is selected from hydrogen and a methyl group.