Olefin polymerisation may be catalysed by a wide range of catalytic materials. Described herein is a heterogeneous olefin polymerization catalyst comprising a porous particulate support material having impregnated therein a metallocene catalyst the metal atom whereof is bound to an amide group which is not bound to an eta -ligand of the metallocene, or the reaction product of a said metallocene catalyst and a co-catalyst.
