A heat-sensitive lithographic printing plate precursor is disclosed which comprises a hydrophilic support and an oleophilic coating comprising an infrared absorbing agent and a polymer, which comprises a phenolic monomeric unit wherein the phenyl group of the phenolic monomeric unit is substituted by a group having the structure —N═N-Q wherein the —N═N— group is covalently bound to a carbon atom of the phenyl group and wherein Q is an aromatic group and wherein the substitution increases the chemical resistance of the coating.