Electrical switch for a medium or a high voltage gas insulated electrical equipment comprising: a first electrical contact configured to move axially along a longitudinal direction (X-X) of the first electrical contact to electrically engage a second electrical contact, a mobile body partially delimiting a compression chamber to be filled with an arc extinguishing fluid, wherein the mobile body comprises an upper wall of the compression chamber, wherein the upper wall is configured to be the nearest wall of the mobile body to the second electrical contact, a fixed body comprising a bottom wall of the compression chamber, wherein the bottom wall closes the compression chamber axially opposite to the upper wall of the mobile body, wherein the compression chamber comprises at least an opening through which the arc extinguishing fluid is configured to flow towards an electric arc formed between the first electrical contact and the second electrical contact when the first electrical contact electrically disengages the second electrical contact to blow out the electrical arc, wherein the mobile body and the fixed body surround the first electrical contact, wherein the mobile body acts as a piston expelling arc extinguishing gas out of the compression chamber when the mobile body moves axially opposite to the second electrical contact, wherein the mobile body moves axially when the first electrical contact electrically disengages the second electrical contact by moving axially, characterized in that the electrical switch comprises an actuation mechanism configured to move the first electrical contact and the mobile body axially and in a same way with different speeds relative to the fixed body, characterised in that the actuation mechanism comprises a disconnecting lever, at least a linking arm connecting the disconnecting lever to the mobile body by at least a first link, and wherein the first electrical contact is connected to the disconnecting lever by at least a second link, wherein the actuation mechanism comprises a rudder through which the first electrical contact is configured to extend and to move axially, wherein an end of the linking arm is fixed to the rudder, and wherein the actuation mechanism comprises at least a traction rod extending from the rudder to the mobile body to move the mobile body axially relative to the fixed body, wherein the actuation mechanism comprises a slave connecting rod connecting the first electrical contact to the disconnecting lever by at least a link. a first electrical contact configured to move axially along a longitudinal direction (X-X) of the first electrical contact to electrically engage a second electrical contact, a mobile body partially delimiting a compression chamber to be filled with an arc extinguishing fluid, wherein the mobile body comprises an upper wall of the compression chamber, wherein the upper wall is configured to be the nearest wall of the mobile body to the second electrical contact, a fixed body comprising a bottom wall of the compression chamber, wherein the bottom wall closes the compression chamber axially opposite to the upper wall of the mobile body, wherein the compression chamber comprises at least an opening through which the arc extinguishing fluid is configured to flow towards an electric arc formed between the first electrical contact and the second electrical contact when the first electrical contact electrically disengages the second electrical contact to blow out the electrical arc, wherein the mobile body and the fixed body surround the first electrical contact, wherein the mobile body acts as a piston expelling arc extinguishing gas out of the compression chamber when the mobile body moves axially opposite to the second electrical contact, wherein the mobile body moves axially when the first electrical contact electrically disengages the second electrical contact by moving axially, characterized in that the electrical switch comprises an actuation mechanism configured to move the first electrical contact and the mobile body axially and in a same way with different speeds relative to the fixed body, characterised in that the actuation mechanism comprises a disconnecting lever, at least a linking arm connecting the disconnecting lever to the mobile body by at least a first link, and wherein the first electrical contact is connected to the disconnecting lever by at least a second link, wherein the actuation mechanism comprises a rudder through which the first electrical contact is configured to extend and to move axially, wherein an end of the linking arm is fixed to the rudder, and wherein the actuation mechanism comprises at least a traction rod extending from the rudder to the mobile body to move the mobile body axially relative to the fixed body, wherein the actuation mechanism comprises a slave connecting rod connecting the first electrical contact to the disconnecting lever by at least a link.