1998 306 LX Central Locking Issue?

hi i wonder if anyone can help me.

I have a 306 LX 1998.

Today when i approached my car and pressed the remote central locking button on my key, nothing happened. I then put the key in the drivers door and turned, only that door unlocked and not the remaining 3 or boot. I then put they key in the ignition turned, nothing, absolutely nothing at all.

Now i don't know anything about cars and the way they work really. But am i right in thinking this may be due to an immobiliser not being disarmed as a result of the central locking not working.

Is there a way to bypass this?

Over the past few days we've had a hell of alot of rain and as a result my car leaked quite badly on the drivers side, this has probably caused a short in the drivers door or cable trim along the bottom under the door.

I could wait with my fingers crossed to wait for it to dry out, but was wondering if there was a bypass.