Client has introduced a delay to the programme via inclusion of their activities

As above. NEC 4 option A. There is an accepted contract programme and the client has requested the inclusion of some of their activities which affect the works and push out the end date. This has also delayed procurement. The revised programme with these activities has been accepted by the PM. Client/PM are refusing to accept a CE for the delay and/or responsibility that their actions have caused the delay. It is difficult to cite a specific clause to deal with the event as there are nuances to the clauses under which it could be applied. I believe it should be a simple case of measuring the delay between the two programmes as it has occurred due to the client introducing their activities into the programme. To be clear these activities affect the works and create constraints as to what can take place and when. There is a clear difference between two programmes and the reason it has been delayed is not due to the Contractor but the PM/Client. I know NEC states that accepting a programme which has been changed/delayed does not necessarily comprise a CE but in this case surely it does as it has occurred due to the PM requesting the change. Thoughts?

I don’t think that your starting point should be the revised programme - you will use that to support the proposed alterations to the (previous) Accepted Programme of the CE quotation, if the CE is accepted. Your focus should be on what were the PM’s/Client’s actions that have delayed your works based on the previous Accepted Programme*; go to the list of events (clause 60.1) and see which ones suit your case.

Should you overcome the CE acceptance issue, you can then demonstrate the delay as mentioned above - see clause 62.2. At that stage, since the revised programme has been accepted, I don’t see how the PM would deny the time impact. However, you need to get the CE(s) accepted first following the notification process etc.

*Admittedly, things are somewhat complicated by the latest revised programme, which reflects the changes, now being the Accepted Programme but I cannot see any other way around it.