Thanks for all of your replies.
The decision was made that he was not diabetic after a glucose curve was carried out.
I have thought about trying another vet and after your comments I will now do so.
I think there are now several problems that have possibly been caused by the primary illness...
I wondered if anyone had any ideas as to what could possibly be wrong with my cat.
It all started in spring of this year (2006). Skippy (my cat) started to beg for more food despite the fact he had always been a picky eater with a small appetite and only ever eating one brand and type of food...