Having just read this I am at a loss as to why each area doesn't have a part time school, where half the kids come, say, Mon-Wed dinnertime, then the other half do wed dinnertime- Fri. They could do longer days, or maybe do a kind of flexischool arrangement where they are home educated for the other days.
We would still need the same amount of teachers, for all the planning and marking etc, but it would give them a bit more flexibility too, for things like cover, and the school would have double the funding for it's size, so could get better facilities - there would be, say, 420 children registered (and funded for) but only 210 of them would actually be using the school at any one time.
I know that longer, but fewer, days would work better for a lot of parents too, jobs and travel wise - my DD goes to the only school that had a place that we could get to, and it takes me up to an hour to do the school run on the bus. Luckily my FIL helps out, but that would be ten hours a week travelling, worse if DD2 was at the school nursery that only does half days - it would practically be a part time job.
Obviously it couldn't be every school, or parents who need to work or who don't want to change at all wouldn't have a choice, but if we are so overcrowded, I'm sure that there is at least two classes worth of kids in each area that would like to be half and half HE and school. I know there are at least two classes worth of reception children crowbarred in around our town - there are only 18 classes worth of children in the whole town, but they are somehow squished into the space for 16. I'm sure it is much worse in places like London.
Or am I missing something?