<p>Aqueous coating composition for a plastics, especially a polypropylene, substrate comprising a stable aqueous dispersion derived from dispersing into water with the aid of a surfactant(s) an organic solvent solution of a composition comprising a chlorinated polyolefine(s), at least one olefinically unsaturated monomer which is polymerisable to a polymer during and/or after coating formation and a filmogenic polymer(s).</p>