A cable includes at least one electrical conductor and at least one extruded covering layer including a thermoplastic polymer material in admixture with a dielectric liquid, wherein the thermoplastic polymer material includes (a) at least 75% by weight, with respect to the total weight of the thermoplastic polymer material, of at least one copolymer of at least two α-olefin co-monomers, the copolymer having a melting enthalpy lower than 25 J/g; and (b) an amount equal to or less than 25% by weight with respect to the total weight of the thermoplastic polymer material of at least one propylene homopolymer or propylene copolymer with at least one α-olefin, the at least one propylene homopolymer or propylene copolymer having a melting enthalpy higher than 25 J/g and a melting point higher than 130° C. The covering layer has a melting enthalpy equal to or lower than 40 J/g, and the concentration by weight of the dielectric liquid in the thermoplastic polymer material is lower than the saturation concentration of the dielectric liquid in the thermoplastic polymer material.