When registering as an Interested Party, will it be possible for people to do this in any way other than in writing/ email/ filling in the online form)? Does the IPC have any plans to accept verbal representations by phone?

Anyone who is not a statutory party and wishes to take part in the examination process of a Nationally Significant infrastructure Project (NSIP) needs to register with the IPC using the prescribed registration form.
This is because of the definition of interested party which includes in s.102(1)(e) "the person has made a relevant representation". S.102 (4) further specifies that "a representation is a relevant representation for the purposes of subsection (1) to the extent that (...) (b) it is made to the Commission in the prescribed form and manner (...)".
The 'form and manner' is prescribed in regulation 4 of the Infrastructure Planning (Interested Parties) Regulations 2010 (Interested Parties Regulations) including the information that a registration form must include. Regulation 2 (1) of the Interested Parties Regulations defines registration form as '(...) the form supplied by and obtained from the Commission for the purpose of making a relevant representation and referred to in the notices and publicity given in accordance with regulations 8 and 9 of the Infrastructure Planning (Applications and Procedure) Regulations 2009(j);'.
In other words, the Act requires that relevant representations are made using an IPC form. As our advice note 8 (attachment 1) explains, this can either be done on-line, or a hard copy can be requested and then sent back to us through the post. However, if anyone sends in a form which would be invalid (e.g. because it is incorrectly filled in or unclear hand writing etc) we would call that person and address with them all the necessary points to make it a valid relevant representation. In such cases we always need to send back the amended registration form to the sender in order to verify that what we have understood is what they meant to say. This amended form (with or without further comments from the sender) then needs to be returned back to us so that the representation can be registered as a relevant one.
Once registered, however, interested parties have the right to request to speak at an open-floor hearing.