What qualification are you getting out of your apprenticeship? I know people who have done mechanical engineering apprenticeships that have given them a higher qualification, which they are now working towards degree level with in their own time.
My cousin also got some vocational higher qualification on some apprenticeship with Kent uni, working some days and attending classes other days, now he has an electrical engineering job in Kent on salary with his employer funding him on getting his degree 2 days a week in classes.
I have some experience in the field of mechanical engineering, and from my experience (admitidly limited) hands on knowledge/ experience is just as if not more valuable than theory knowledge.