An electrical connector comprising, a first connector housing and a second connector housing configured to be coupled to one another through an opening of a panel, wherein the second connector housing is configured to fit inside the first connector housing; and a mate assist mechanism comprising a lever pivotably and sealingly mounted to the outside of the first connector housing, wherein the mate assist mechanism is configured to couple and uncouple the first and second connector housings (100, 300) by pivoting of the lever between a pre-lock position and a locked position; the lever comprising a locking mechanism configured, upon pivoting the lever to the locked position, to engage with a corresponding locking mating member of the second connector housing to secure the first and second connector housings (100, 300) in a mated state, and a blocking element configured to cooperate when the first and second housings (100,300) are in an uncoupled state or the second connector housing is absent, with a blocking surface of the first connector housing to maintain the lever in the pre-lock position; characterised in that the locking mating member of the second connector housing comprises an activation element configured to cooperate, when the first and second connector housings (100, 300) are in a pre-mated state, with a corresponding activation member on the locking mechanism of the lever, the activation element is configured to exert a biasing force on the corresponding activation member of the locking mechanism causing the lever arm to be displaced outwardly from the first connector housing such that the blocking element of the lever is released from the blocking surface of the first connector housing and the lever becomes free to move to the locked position, and in that the first connector housing comprises a lever seal for sealing an opening between the first connector housing and the lever for accommodating the lever, and a panel seal for sealing an opening between the first connector housing and the panel. a first connector housing and a second connector housing configured to be coupled to one another through an opening of a panel, wherein the second connector housing is configured to fit inside the first connector housing; and a mate assist mechanism comprising a lever pivotably and sealingly mounted to the outside of the first connector housing, wherein the mate assist mechanism is configured to couple and uncouple the first and second connector housings (100, 300) by pivoting of the lever between a pre-lock position and a locked position; the lever comprising a locking mechanism configured, upon pivoting the lever to the locked position, to engage with a corresponding locking mating member of the second connector housing to secure the first and second connector housings (100, 300) in a mated state, and a blocking element configured to cooperate when the first and second housings (100,300) are in an uncoupled state or the second connector housing is absent, with a blocking surface of the first connector housing to maintain the lever in the pre-lock position; characterised in that a locking mechanism configured, upon pivoting the lever to the locked position, to engage with a corresponding locking mating member of the second connector housing to secure the first and second connector housings (100, 300) in a mated state, and a blocking element configured to cooperate when the first and second housings (100,300) are in an uncoupled state or the second connector housing is absent, with a blocking surface of the first connector housing to maintain the lever in the pre-lock position; characterised in that the locking mating member of the second connector housing comprises an activation element configured to cooperate, when the first and second connector housings (100, 300) are in a pre-mated state, with a corresponding activation member on the locking mechanism of the lever, the activation element is configured to exert a biasing force on the corresponding activation member of the locking mechanism causing the lever arm to be displaced outwardly from the first connector housing such that the blocking element of the lever is released from the blocking surface of the first connector housing and the lever becomes free to move to the locked position, and in that the first connector housing comprises a lever seal for sealing an opening between the first connector housing and the lever for accommodating the lever, and a panel seal for sealing an opening between the first connector housing and the panel.