Use cable ties - see
http://www.selfix-uk.co.uk/Belt-fitting.html
http://reynoldsbooks.weebly.com/1/post/2010/09/how-to-replace-the-belt-on-a-hotpoint-wma58-washing-machine-the-quick-and-easy-cable-tie-method.html
It took me ages to find this solution but it is really brilliant!
Peter Reynolds, September 2010