Compositions of viscoelastic surfactant and hydrophobically modified polymer as aqueous thickeners

An aqueous viscoelastic composition comprising

• a. at least one viscoelastic surfactant selected from the group consisting of amine oxide and amidoamine oxide surfactants, and
• b. at least one hydrophobically modified polymer, which:
• i. is formed from polymerization of ethylenically unsaturated monomers;
• ii. has a number average molecular weight of from 1,000 to 90,000 Da;
• iii. to a level of least 0.1 mole %, based on the amount of monomer units in the polymer, contains monomeric units each covalently bonded to a pendant, optionally alkoxylated, hydrocarbyl group having from 6 to 40 carbon atoms, said pendant, optionally alkoxylated, hydrocarbyl group being connected to the backbone of said hydrophobically modified polymer via a non-ester containing linking group.