There is provided a vacuum switching assembly for switching an AC or DC current. The vacuum switching assembly comprises a vacuum switch. The vacuum switch includes: first and second electrodes (20, 22) located in a vacuum tight enclosure, the vacuum tight enclosure containing a gas or gas mixture, the first and second electrodes (20, 22) defining opposed electrodes being separated by a gap, each of the first and second electrodes (20,22) being connectable to a respective electrical circuit carrying an AC or DC voltage; and a pressure controller (36) configured to control an internal pressure of the vacuum tight enclosure, wherein the pressure controller (36) is configured to selectively switch the internal pressure of the vacuum tight enclosure between: a first vacuum level that permits formation and maintenance of a glow discharge in the vacuum tight enclosure to allow a current to flow between the first and second electrodes (20, 22) via the glow discharge so as to turn on the vacuum switch; and a second vacuum level that inhibits formation and maintenance of a glow discharge in the vacuum tight enclosure to prevent a current from flowing between the first and second electrodes (20, 22) via the glow discharge so as to turn off the vacuum switch.