Kath - I had this problem only today and fixed it in 2 minutes - mainly because it happens regularly and I've got the technique...
My similar blockage is not in the toilet itself but in the inspection pit outside - the outlet drain pipe gets blocked with paper debris. Rather than push the blockage further up the drain pipe I pull it back into the pit and suddenly it all drains away.
I tell you this in an attempt to save you time - if you have an inspection pit with a metal cover outside it takes just a few moments to lift the lid and peek inside - then you'll know where to spend your efforts.
In the toilet - if the outside drains are clear - You may try a drain cleaning spring or even a length of garden hosepipe.
http://ecx.images-amazon.com/images/I/31-0V6LXDZL.jpg
Good luck...
Peccavi
January 2010