Frank I can't quite believe it but I managed to get there in the end. Link to photo below.
http://homepage.ntlworld.com/laurence.rudolf/Temp%20Brake%20Light%201.jpgI could not have done this without your invaluable help and Paul from MES Ltd who supplied the Y-Splitter.
I did not check what type of connectors I had & as my car is from 1998 it turned out to be bullet as opossed to the later econo seal type. This meant that to solve the problem I had to change the connectors working inside the tyre well. Space was tight but determination prevailed.
When the temporary brake light is not in use it is easily removed.The female connecter is held in place by velcro as Frank suggested. I then made a loop using a cable tie & used another cable tie to secure it to the velcro. Now it is very easy to pull out with a hook. This saves the need to remove the spare wheel everytime you want to connect the temporary break light.
The Y-Splitter made this all possible. I did not think that I would be able to tackle this job myself but Frank spurred me on. Now I am one happy Morganeer!