A pressure restraining enclosure for cables can include, for example, a first cable including a conductor and an oil-containing layer surrounding the conductor, and a second cable having a conductor. A splice can connect the conductor of the first cable with the conductor of the second cable. A pressure restraining sleeve can overly the splice and the conductors of the first and second cables. Several fasteners can be applied to several locations on the pressure restraining sleeve to tighten the pressure restraining sleeve around the splice and portions of the first and second cable. Embodiments of the pressure restraining enclosure can be used in the form of a sleeve on a single core cable, or alternatively as a body and a separate sleeve on multiple core cables such as three-core cables.