I do know a bit about this as I was working in Northampton about 9/10 years ago and was heavily involved in the setting up of the City Supporters Trust at the time. The first person to set up a Supporters Trust was a Northampton fan called Brian Lomax, who did it for them to make them a fan-owned club when they were in trouble previously. I spoke to Brian who wasn't actively involved but passed me on to the people who were.
I ended up in the Director's Box for a midweek game against Brentford, who were also fan owned and whose chairman was one Greg Dyke (who was a great help I might add along with Jon Gosling, one of the supporter directors). I had a chat with David Cardoza who made no secret of the fact that he wasn't a football fan when he got involved but was a property developer. But to give him his due, he's been involved with Northampton now for many years. The plan was to redevelop the land behind the stadium but I can't quite recall whether he was planning to finance that or the council was. I think he said the council would give them the land and he would develop it in return for allowing expansion of the stadium. In return for doing all this, the club had allowed him to acquire the majority shareholding but the fans still had some shares and were guaranteed a seat on the board. I do remember there was a lot of talk at the time about problems getting the council to do anything.
Given the timing, I suspect that the financial crash probably put paid to the prospect of any re-development for a while but I gather that revised plans were put in place a couple of years ago, presumably involving this council loan. From what I can see, Cardoza isn't being very communicative and the NTST are asking a lot of questions and have demanded a board meeting to find out what's going on.
