The last couple of days neither of my keys have operated the central locking on or off unless I am stood in one spot close to the car. Both keys have good batteries so I am wondering if there is an issue with the receiver. Any ideas ?

 

I had a similar issue with my Peugeot a few years ago, I had to get closer and closer to the car over time, and eventually the receiver just totally died, and wasn't even picked up by the scan tool anymore.
Sounds like yours is doing something similar.
I'd say be prepared for it to die at any time and take whatever precautions are necessary, if any.
In my case the "precaution" was to finally get around to fixing the door lock, because the key sometimes wouldn't work in it, and none of the other doors even had manual locks on them. So if the remote stopped working I would have been screwed.

 

Got this sorted . It turned out that the tiny flap on the ignition barrel was not fully closing when you took the key out. It seems that it isn't just a cover but is a switch that tells the alarm that the key has been removed.It was making poor contact and so the key had to be really close for the signal to work. Silicone sprayed the barrel and worked it a few times and now all fine. (so far)

 

SEARCH IS A MARVELOUS TOOL

https://www.jaguarforums.com/forum/x...t-work-178546/

Post #4 =
https://www.jaguarforums.com/forum/x...orking-249919/

post #2 =
https://www.jaguarforums.com/forum/x...g-lock-241529/

Etc etc....

 

The problem with liquid lubes in Tibbe locks is that the discs can become gummy and not slide properly.

Instead, you want to use dry lube (graphite).