Changes made by Electricity (Class Exemptions from the Requirement for a Licence) 1997
S.I. 1997/989
Made to Electricity (Class Exemptions from the Requirement for a Licence) 1995
2 changes. All changes made by Electricity (Class Exemptions from the Requirement for a Licence) 1997
From legislation.gov.uk's record of changes, the official one: see it there.