AllisonUK....You are not alone!! I think everyone who is owned by a cat has experienced loss of sleep! If you browse through some of the previous posts, such as a topic started a few months ago (link below), you will see how some of us have dealt with this. My cat, Andy, still tries to wake me up early occasionally but it has lessened somewhat lately. I am usually quite successful just banning him from my room if it gets too bad. My other cat, Trevor, is a "door thumper" so it's sort of hard to ignore him. Here's hoping you get some relief soon, but I just wanted you to know I sympathize!
http://petoftheday.com/talk/Forum9/HTML/000026.html