Abstract: A submarine cable core comprising a conductor which is surrounded by at least an inner semiconductive layer, an insulation layer and an outer semiconductive layer in that order; wherein said insulation layer comprises: a low density polyethylene homopolymer or low density polyethylene copolymer with at least one polyunsaturated comonomer and optionally one or more further comonomers; and, a copolymer comprising at least one polar comonomer selected from the group consisting of an alkyl acrylate, an alkyl methacrylate or vinyl acetate, wherein the amount of polar monomer units in the insulation layer is from 1 to 150 micromol per gram based on the total amount of polymer components in the insulation layer.