Hi Paul, thanks very much for your reply. The engine does not turn over - the alarm sounds and will not go off ? (does this mean that there is power in the battery). I went to get spare key fob - same thing. The fob produces absolutely no response - neither fob. I can unlock the door manually using key. The alarm goes off. Key in ignition does nothing - no lights, no turn over, no turning off alarm = totally unresponsive using both key fobs. seems strange that both key fobs not working ? Called Citroen dealer earlier this afternoon - not very helpful, just was advised to get car to them, which is not easy. Cannot even lower the window as nothing works (apart from the alarm). I may try disconnecting the battery tomorrow, when daylight, and try resetting the keys as you suggest.