Abstract: In a single core or multi-core electric power cable, the dielectric screen of the or each cable core is surrounded by a moisture barrier consisting of a composite tape comprising a carrier layer of plastics material which is sandwiched between radially inner and outer metal foils bonded to the major surfaces of the carrier layer and electrically connected together. The composite tape surrounds the dielectric screen with its longitudinally extending edges overlapping and secured to one another throughout their lengths to form a moisture-tight seal. The moisture barrier so formed effects electrical interconnection between the underlying dielectric screen and a surrounding neutral, earth or ground conductor of the core. The moisture barrier is less expensive than moisture barriers hitherto proposed and used.