Abstract: Electrical cable for high and very high voltages includes a plurality of conductors, at least one semiconductive layer, a stratified insulation impregnated with an insulating fluid and an external metal sheath. The insulation is constituted by a paper/polypropylene/paper laminate, wherein polypropylene has been subjected to a treatment such as to allow the laminate to swell up by less than 5% after immersion in decylbenzene at 100.degree. C. for at least 3 days.

Abstract: An electric power cable having a Milliken-type conductor comprising at least four sectors, the conductor being paper-insulated and oil filled and each sector comprising metal wires stranded together. Each wire is covered with a layer of a cross-linked synthetic resin having a thermal classification of 120.degree. C., a CEI resistance to abrasion of at least 50 cycles, a CEI thermal pressure value higher than 170.degree. C. and an insulating oil contaminating effect of substantially zero, such resin also being substantially completely volatizable by the heat used for joining cables by welding. Preferred resins are a polyvinyl-acetal resin, such as a polyvinyl-formal resin, cross-linked with a phenol resin and, optionally, a melamine resin and such with the addition of a blocked isocyanate.