GoldenBear, Let me get this right. You were renting. in a nice area. And you chose this area, because it had a good school, among other reasons. You wanted to buy. You got your son into the good school. But he buying never worked out. Then you moved. Now you can't get into the equally good local schools. So you have to travel some distance, back to your old area, to the good school , that your son is still in.
Is this right? And your complaint is? Have you seen how ironic this is.
As if you are saying : "I was renting to get my son into the good school. Then I moved out of catchment". This is the VERY thing that most people complain, that people do, in order to get their children into the good school. You have done the absolute most criminal thing,
as far as school application processes go.
And you claim that moving is not that easy? 5 years to move. In a 5 year period, people are unable to move? Really. I find that hard to believe. Why can they not move? Please give me the reasons, because I don't understand them. Are you seriously saying that people can't move, in 5 years. I disagree.
If you move to a house that you can afford, in an area that you can afford, I consider this a not THAT difficult thing to do. If you accept your budgetary constraints. When you decide to have children, you plan, what job you will be able to do, what childcare you may need. What you can afford. Where you want to live. Which schools could you/do you have a chance of getting into . Then you move. When your child is 1 or 2, or 3 or 4. 5 years you've got. To sort it all out. But you claim this is not possible.
Other people, help me out here. I can't be the only one, who once I realised that I was going to have a child, who was going to need to go to a school, thought about where it was that would be available to me.
Funny. I managed it. I know possible 100 people who have lived here for a long time, or moved, planned it all and sorted it all, prior to their children starting school.
And :
"There is a serious shortage of affordable family homes where I live and therefore 2/3 bedroom flats are not cheap but are what a lot of families live in. My DP works in this city so what do you suggest we do- move away from an entire city because we can't afford to live next to any of these 'outstanding', oversubscribed schools. Neither can we afford a family home next to the 'Good' schools as they are often in suburban areas where the price of houses is out of our reach by 50,000. If we are going to have to live in a flat I'd rather it was near the 'outstanding' schools. We are the lucky ones as well, in that we are at least able to buy a flat."
You can't afford to live where you want? You want to live in a nice area. With good schools. But you can't afford to. You want to live in an area that you can't afford. 
Errr yeah? AND ? Join the rest of the population Love. My dh does a 50 mile commute to near Brighton for his latest job.
We live where we can afford to live.
I fancy living in Ascot, Hampstead or Kensington. But we can't afford it.
So were live here, where we can afford it.
You should try it, sometime. It makes life easier.