Regulation 53

Any person, other than the grantee, claiming to have an interest in a grant of protection which is the subject of an application under rule 50 may apply to the Registrar in writing for permission to intervene.

The Registrar may, after hearing the parties concerned if he so required, refuse permission to intervene, or grant permission to intervene upon such terms (including any undertaking as to costs) as he thinks fit.

Any person granted permission to intervene shall, subject to the terms and conditions imposed in respect of the intervention, be treated as a party to the proceedings in question.