The present invention relates to improved polymeric compositions based on ethylene-vinyl ester and ethylene-alkyl acrylate copolymers which can be crosslinked to provide insulation coatings for wire and cable products. The copolymer compositions contain a hydrated inorganic filler, an alkoxysilane, an antioxidant and a polymeric processing additive. Organic peroxides are preferably employed to facilitate crosslinking. An improved method for providing the improved compositions and electrical conductors coated with the crosslinkable polymeric compositions are also provided by the invention.