A method of electrically separating longitudinal segments of at least one metallic sheath and an outer semi-conductor layer of a high voltage mass impregnated direct current, HVDC MI, cable, the HVDC MI cable comprising, from the centre of the cable; at least one conductor, at least one mass impregnated insulation layer, the outer semi-conductor layer and the at least one metallic sheath, the method comprising the steps of; - exposing a section of the outer semi-conducting layer by removing the at least one metallic sheath within said section, - within the exposed section of the outer semiconductor layer, exposing a section of the at least one mass impregnated insulation layer by removing the outer semiconductor layer between a first and a second position (P1, P2), - forming at least one insulation tape layer (100, 101) by wrapping a insulating tape onto the cable within at least part of the exposed section (L 1) of the outer semiconductor layer, - forming at least one semi-conducting tape layer (200, 201) by wrapping a semi-conducting tape from at least one of the first and the second positions (P 1, P2) in a direction towards the opposite position (P1, P2) thereby extending the outer semi-conducting layer, such that the semi-conducting tape layer (200, 201) in the longitudinal direction overlaps a section of the of the outer semiconductor layer or an extension thereof thereby forming an overlap section and such that within the overlap section the at least one semi-conducting tape layer (200, 201) is radially electrically separated from the exposed section of the of the outer semiconductor layer or the extension thereof by the at least one insulation tape layer (100, 101), - applying an insulator mantle around the circumference of the cable at least spanning the exposed section of the outer semi-conducting layer, - securing said insulator mantle to the HVDC MI cable by securing one metallic flange to each side of the insulator mantle and soldering the metallic flanges to the metallic sheath, - providing said metallic flanges with electric connections, wherein the method further comprises the step of providing at least one of said metallic flanges with an impregnation fluid inlet, and providing impregnation fluid either pressurized or not pressurized into the HVDC MI cable through said fluid inlet. at least one conductor, at least one mass impregnated insulation layer, the outer semi-conductor layer and the at least one metallic sheath, the method comprising the steps of; - exposing a section of the outer semi-conducting layer by removing the at least one metallic sheath within said section, - within the exposed section of the outer semiconductor layer, exposing a section of the at least one mass impregnated insulation layer by removing the outer semiconductor layer between a first and a second position (P1, P2), - forming at least one insulation tape layer (100, 101) by wrapping a insulating tape onto the cable within at least part of the exposed section (L 1) of the outer semiconductor layer, - forming at least one semi-conducting tape layer (200, 201) by wrapping a semi-conducting tape from at least one of the first and the second positions (P 1, P2) in a direction towards the opposite position (P1, P2) thereby extending the outer semi-conducting layer, - exposing a section of the outer semi-conducting layer by removing the at least one metallic sheath within said section, - within the exposed section of the outer semiconductor layer, exposing a section of the at least one mass impregnated insulation layer by removing the outer semiconductor layer between a first and a second position (P1, P2), - forming at least one insulation tape layer (100, 101) by wrapping a insulating tape onto the cable within at least part of the exposed section (L 1) of the outer semiconductor layer, - forming at least one semi-conducting tape layer (200, 201) by wrapping a semi-conducting tape from at least one of the first and the second positions (P 1, P2) in a direction towards the opposite position (P1, P2) thereby extending the outer semi-conducting layer, such that the semi-conducting tape layer (200, 201) in the longitudinal direction overlaps a section of the of the outer semiconductor layer or an extension thereof thereby forming an overlap section and such that within the overlap section the at least one semi-conducting tape layer (200, 201) is radially electrically separated from the exposed section of the of the outer semiconductor layer or the extension thereof by the at least one insulation tape layer (100, 101), - applying an insulator mantle around the circumference of the cable at least spanning the exposed section of the outer semi-conducting layer, - securing said insulator mantle to the HVDC MI cable by securing one metallic flange to each side of the insulator mantle and soldering the metallic flanges to the metallic sheath, - providing said metallic flanges with electric connections, - applying an insulator mantle around the circumference of the cable at least spanning the exposed section of the outer semi-conducting layer, - securing said insulator mantle to the HVDC MI cable by securing one metallic flange to each side of the insulator mantle and soldering the metallic flanges to the metallic sheath, - providing said metallic flanges with electric connections, wherein the method further comprises the step of providing at least one of said metallic flanges with an impregnation fluid inlet, and providing impregnation fluid either pressurized or not pressurized into the HVDC MI cable through said fluid inlet.