Letters of Rep and objectors' names and addresses - Public forum - Planning Advisory Service (PAS)

We have been challenged on the requirement to provide names and addresses on letters of rep.  The person complaining only wants to provide their email address.  Can anyone provide me with a link to any legislation/advice that names and addresses are required.  If there is no requirement then surely this could be used as a loophole to bombard a local authority with letters of rep on one application by creating multiple email addresses.  We do advise on our website that names and addresses are required but would like this to be backed up by legislation if there is some.