A vascular closure device, comprising: a deployment assembly that is elongate along a longitudinal direction and that has a distal end and a proximal end spaced from the distal end in a proximal direction that is aligned with the longitudinal direction; a sealing unit carried by the deployment assembly, the sealing unit including a suture coupled to the deployment assembly and a toggle attached to the suture and disposed at the distal end of the deployment assembly; a tamper carried by the deployment assembly and disposed along the suture with respect to the sealing unit in the proximal direction, the tamper including a lumen that receives the suture such that the tamper is slidable along the suture; and a locking assembly coupled to the tamper so as to selectively inhibit advancement of the tamper along the suture in the distal direction toward the sealing unit, wherein the locking assembly is adapted to transition from A) a locked configuration where the tamper is inhibited from sliding along the suture, into B) an unlocked configuration where the tamper is slidable along the suture in the distal direction and into contact with the sealing unit, wherein the vascular closure device is characterised in that the locking assembly includes at least one tab (160, 150, 155), the at least one tab including a respective opening that is sized to receive the tamper therethrough, wherein the at least one tab (160, 150, 155) is moveable from a first position, where the tamper is inhibited from the sliding along the suture by the at least one tab (160, 150, 155) such that the locking assembly is in the locked configuration, to a second position, where the tamper is slidable with respect to the at least one tab (160, 150, 155) and along the suture such that the locking assembly is in the unlocked configuration. a deployment assembly that is elongate along a longitudinal direction and that has a distal end and a proximal end spaced from the distal end in a proximal direction that is aligned with the longitudinal direction; a sealing unit carried by the deployment assembly, the sealing unit including a suture coupled to the deployment assembly and a toggle attached to the suture and disposed at the distal end of the deployment assembly; a tamper carried by the deployment assembly and disposed along the suture with respect to the sealing unit in the proximal direction, the tamper including a lumen that receives the suture such that the tamper is slidable along the suture; and a locking assembly coupled to the tamper so as to selectively inhibit advancement of the tamper along the suture in the distal direction toward the sealing unit, wherein the locking assembly is adapted to transition from A) a locked configuration where the tamper is inhibited from sliding along the suture, into B) an unlocked configuration where the tamper is slidable along the suture in the distal direction and into contact with the sealing unit, wherein the vascular closure device is characterised in that the locking assembly includes at least one tab (160, 150, 155), the at least one tab including a respective opening that is sized to receive the tamper therethrough, wherein the at least one tab (160, 150, 155) is moveable from a first position, where the tamper is inhibited from the sliding along the suture by the at least one tab (160, 150, 155) such that the locking assembly is in the locked configuration, to a second position, where the tamper is slidable with respect to the at least one tab (160, 150, 155) and along the suture such that the locking assembly is in the unlocked configuration.