Looks as though it is available from here:
http://www.theiet.org/publishing/books/wir-reg/onsite-guide-17-edition.cfm
Have just ordered a copy - see if it turns up in the next few days.
http://www.theiet.org/publishing/books/wir-reg/onsite-guide-17-edition.cfm
Have just ordered a copy - see if it turns up in the next few days.