The drivers door on my 1997 Audi A4 saloon is stuck shut. It will not open from either the outside or the in. I think it is the lock that has broken but not sure.

I can open the car by using the key in the passenger door - and although the central locking pump runs, it does not unlock the other doors. The pump runs for a long time before stopping. Would a broken pump, or leak in the tubes stop the drivers door from unlocking and opening even with the key?