It went to the Ford dealer today and they checked it over. The MAF had been unplugged. Once back in, up the road and all the codes cleared. It seems fine. Now I have to sort an overboosting problem out and a small leak onto the oil cooler, but its definitely running better.

Don't get why the MAF being unplugged would have caused an ESP system fault, but I'm no mechanic, just pleased its better.