tailgate door lock on disco tdi 300

Hi, i recently dicovered that the rear door has not been locked ,when i lock up with the fob the button drops down but if you go to open it with the handle it opens ,I then have too lock it with the key, now i have a problem with the front passenger door i have to lean over and lift up the button to let people in ,i know this is the spring and if the problem with the tail gate door is spring related too i will go on ebay to buy the spring kit .
thanks
ETR

spring kit needed - bit of bugger to fit but does cure all

thanks e bay it is then
ETR