A Return to Poor Doors

The Guardian has a brief story about a development in Southwark having a poor kids playground and a richer kids playground in a situation akin to the "poor doors" policy.  The story says that this is outside planning rules, but I suspect that actually it is a case of the planning authority not being on the ball.  I think that the developer probably applied for a variation of the planning permission, and the Authority nodded it through without understanding the implications.  Permission having been granted, there is nothing it can now do about it.