Actually @Lost all faith the students we train still have to pay back their earnings wherever they are on Earth. I checked up on this for my children who are being slowly sold off to the Student Loans Company as we speak.
Here's the list the nice people have provided showing the earnings threshold at which you have to start paying ££ back to blighty for each country.
http://www.studentloanrepayment.co.uk/portal/page?_pageid=93,6678668&_dad=portal&_schema=PORTAL