rear hatch switch won't engage to unlock the tail gate

This failure to disengage the hatch locking mechanism was an intermittant probem that has become a permanent mal function. It could be a failed celanoid or switch. The locks on all four of the doors, which operate using the same fuse as the tail gate, all function appropriately. Without a mechanical means of operating the tail gate latch there appears to be no possible way to open the tail gate. This makes no sense so there must be some sort of by pass available.