Hi Iain,
It seems to differ depEnding where you are in the UK. For me, I have an annual review and a mini check up each year. The annual review involves a fasting blood test (normally a week before), urine sample, check of the feet, retina screening (done separately). Minin check up is a non-fasting blood test and a general chat.
I'd call up and ask whether you need to fast and if you need to provide a urine sample. If you do get a pot and make sure it's the first wee of the day.
Hope this helps
Em