So, we have power. Mystery solved. The perfect storm of mistakes hit at once. Firstly, all the meters in the meter cupboard have been marked up incorrectly, So the meter guy changed the meter for what he believed was the correct flat. It wasn't. It now transpires that another meter company were on site earlier on the day he lost power. He didn't know this till yesterday after talking to another resident. Turns out that they had isolated the wrong property. This also explains why i had healthy readings at one end and poor at the other, as his tails were still connected in his meter. So as the saying goes..... Every day is a school day. Many thanks for all your help guys!