Gary, firstly best of luck to your son.
Secondly for many on the forum speaking of their own experience (myself included) the world has moved on.
I can't be bothered to list the number of jobs I've had in my life. Part-time, full-time, factory shut down as pipe fitter's mate etc. etc.
Yesterday (just for 'fun') I looked at the number of jobs for unskilled workers on-line in the Dover District and found less than a dozen.
We no longer need ill educated 'grunts' to hoik things around against gravity which is all manual labour is (and I certainly include mining in this).
I seriously don't see a solution for GB plc apart from a drop overall in living standards. There's no way we can keep the economy going by selling each other coffee/burgers or even building houses, in each case we are merely swapping money with each other.
Unfortunately since the coffee / beef/ building materials come from abroad the more we do it the more we dig ourselves into a hole.
Here's the serious figures:-
http://www.statistics.gov.uk/instantfigures.asp