I'd write back.
Dear Sir,
PCN ******
Thank you for your letter dated **** rejecting my representations against the above PCN.
I refer you to s86 of the Traffic Management Act 2004, which creates the prohibition referred to in the PCN. I have reproduced the relevant parts in full because this point needs to be reinforced to the authority:
86 Prohibition of parking at dropped footways etc.
(1)In a special enforcement area a vehicle must not be parked on the carriageway adjacent to a footway, cycle track or verge where—
(a)the footway, cycle track or verge has been lowered to meet the level of the carriageway for the purpose of—
(i)assisting pedestrians crossing the carriageway,
(ii)assisting cyclists entering or leaving the carriageway, or
(iii)assisting vehicles entering or leaving the carriageway across the footway, cycle track or verge; or
(b)the carriageway has, for a purpose within paragraph (a)(i) to (iii), been raised to meet the level of the footway, cycle track or verge.
This is subject to the following exceptions.
(2)The first exception is where the vehicle is parked wholly within a designated parking place or any other part of the carriageway where parking is specifically authorised.
A “designated parking place” means a parking place designated by order under section 6, 9, 32(1)(b) or 45 of the Road Traffic Regulation Act 1984 (c. 27).
As you have confirmed that the location lies within a 'parking bay', then it follows as a matter of law that the exception specified in s86(2) applies.
I urge the authority to reconsider its decision and if in doubt then I recommend that the matter is referred to senior management.
If I am required to make representations against a NTO on these grounds and if such representations are rejected then I shall press for costs at adjudication.
YF