In reply to L'Eeyore:
Do you live local? I've got family in the area and walked the perimeter in October or November last year to see what they were up too, it was possible to walk all the way round (at low tide). Obviously that might have changed since.
The coast path is closed as the site has been fenced off right to the cliff edge, but you could walk along the existing sea wall footpath beneath A and B stations, then drop down onto the beach for about a mile until the cliff drops and you can scramble back up. Make sure its low or falling tide if you walk the beach bit, as the high tide level is frequently hard against the cliff, easy to get caught out I would think.
Plenty of CCTV and security patrols inside the fence but no-one seemed to bat an eyelid at me walking round.
It was very muddy when I last walked round, but interesting to see the extent of works already complete. They have obviously sunk a lot of money into the site so far (plus all the road improvement works and new bits of road elswehere), but for all the reasons raised its far from certain to go ahead.
Post edited at 10:04