Probably because the previous consultations rejected the idea.

True and one effect of a neighbouring CPZ would be to cause overspill and make the situation worse. This phenomenon is recognised by the council yet they continue, IMO, to push for them as they are a source of revenue and easier to implement than addressing the root causes such as poor public transport links. For instance, there seems to be a lot of park and ride from East Dulwich and Catford but there are no bus links to HOP station from these local places.