So how much is the compound interest on a student loan after you haven't paid for five years?

I don't know but I guess it's an awful lot and just when you think things are looking up and you get a reasonable bonus for all that extra hard work, will the loan computer decide that your income has suddenly gone up and take most of it off you? My guess is "Yes" but I suggest you ask an M.P. since they were so keen to inflict this on you.
If the universities are so determined to have this kind of fee system, they should be more flexible and allow students to opt in and out on a yearly basis, paying off their degree before it mounts up. I think it is tragic that after years of a fairly egalitarian system, suddenly the most expensive courses to run are only easily available to the kids of rich parents and a handful of the token poor.
If the government wants students to pay, why can't they fund an interest free loan, even if it costs a bit more?  At least you would know where you are. I am not kidding about interest.. You need some hard figures before you look at any deferred payments and no one I know had seen a chart telling you how much you will owe if you haven't reached £21,000 annual salary after five, ten, or fifteen years, or if you take a break or do part time work to fit in with looking after a family.
I'd love an answer and I am really sorry that this is happening to you.