The invention relates to an agent for obtaining a stable aqueous solution comprising a combination of: a polymer made up of: at least one monomer A of acrylic acid and/or methacrylic acid and/or any one of their salts at least one monomer B of alkyl acrylate and/or methacrylate and at least one cross linking monomer D and with at least one compound C corresponding to the following formula (I): R1 O [(EO)n(PO)n (BO)n ] Z (I) where: R1 represents an ethyl isopropyl and/or sec butyl radical [(EO)n(PO)n (BO)n ] represents a polyalkoxylated chain made up of alkoxylated units distributed into block alternating or statistical units chosen from among ethyoxylated units EO propoxylated units PO and butoxylated units BO n n n representing independently of one another 0 or an integer varying from 1 to 150 the sum of n n and n not being zero and Z represents a fatty linear or branched chain of at least 16 carbon atoms.
