The high or very high voltage DC cable has extruded polymeric insulation made out of a styrene-containing material. The material of the insulation is constituted by a mixture comprising polyethylene, a hydrogenated block copolymer of styrene, and an anti-oxiding agent, with the styrene content by mass being 11% to 18%, and the material is not cross-linked. The cable is suitable for use as a DC power cable.