A branch-off connector for an electric power cable has two half shells containing moisture resistant sealing gel that are clamped around the branch-off region to form a sealed housing. A pre-terminated branch cable may be mounted in one of a plurality of orientations on the housing. Electrical connection to the main cable, and thus energisation of the branch cable, can be made subsequently to sealing of the housing around the branch-off region by insulation - piercing screws retained within the housing. Further branch cables can be added to, or branch cables removed from the connector, without disturbing the sealing of the branch-off region of the main cable.