Had a response back from a nice man at the certification office. It appears the Pccc's newfound union status is rather less concrete than it would appear.
As they have declined to be listed, at a small cost of £150, then there are limited investigations carried out as to whether it is indeed a trade union or not. To appear on the "schedule" of trade unions and not the "list" is not sufficient evidence to qualify as a trade union in a court of law.
Additionally, no checks are carried out as to whether the "union" is independent or not. This is only dobe after a request for a "certificate of independence" is received.
So to summarise.
The pccc may not be a trade union
If it is then it is NOT considered to be independent by the certification office.