I posted this topic a week or so ago and swiftly got alot of replies with invaluable help. I just want to say a very big thankyou to those of you who posted replies. We have now had 5 nights uniterrupted sleep. Changed Micky's food to royal canin sensible last Saturday mixed with his usual food 50/50 then 75/25 and today 100% royal canin. I also put on him an old woolen jumper when the nights were very cold and hey presto - he hasn't been getting up. He is pooping less and seems fine. I hope we have finally solved the problem and broken the routine of nightly waking.