What's the MSc in, and where?
Anyway, in all the funding I've had, you only have to pay back money you've claimed and not used. I.e. if you got paid (imagine) 1 years lump sum, and quit after week 3, you'd have to pay it back. I highly, highly doubt you'd owe them money if you had to quit after the year.
Best thing to do is ask. Although remember, you can get a career development loan, at a favourable APR with repayments that don't start until 2-3 months after the course starts. E.g.
http://www.personal.barclays.co.uk/...mefreegroup&value=11607&target=_self&site=pfs