A thought, a thought ...
If you consider Further and Higher Education to be public services then why is that some people think that students, almost uniquely, should pay an additional tax for receiving that service? If you have the need to call for the assistance of a constable you would not expect to find upon receipt of your next payslip that you were paying more tax. If you have the misfortune to require hospital attention you would be surprised to be landed with a bill as you were sent home to recuperate (leaving aside, for the moment, those PFI monsters which charge for access to a television, for parking, and for anything else they can get away with - thus 'almost uniquely). Walking home of an evening using the pavement and the streetlights does not incur an additional charge. Having snow cleared from your path by serving soldiers brought from barracks for the purpose does not leave you with a burden of debt to repay. Using our public libraries will not bankrupt you. Sending children to school does not incur result in a higher rate of tax for decades after they leave.
Why should students be singled out? They have higher earnings over their lifetimes? They'll pay more tax in a progressive system (actually, they'd pay more tax in a flat rate system as well, but I prefer the idea of progressive taxation, it seems fairer). Others don't get the benefit of that education? Yes we do - in the form of doctors, engineers of all kinds, teachers, plumbers, electricians, nurses, town planners (give them a wee break), geologists (they find things that we need, you know), philosophers, and even lawyers - although universities do also produce economists, there's a fly in every ointment.
Of course, there's always the argument that Further and Higher Education don't constitute public services but in that case why do we give them any public money at all? Tuition fees have no place in public education and we should pay for Further and Higher Education out of general taxation because they're part of our civilisation and tax is the price we pay for civilisation. You need a tax system which is fair and raises enough money of course - you wouldn't want to try to run a country on a block grant - and you'd need to be prepared to invest for years before you saw the benefits, but that's OK, the sooner you start the sooner you benefit.