No, you can't do a full degree program and work full time. I very much doubt you legally can on the visa they give you, but more importantly you simply wouldn't have time or energy. I mean, at minimum a 7 hour work day (assuming 0 overtime, quite an assumption), and then, what, at least 3-4 hours studying? Missing all your daytime lectures/seminars? Keep that up and you'll go mad. Especially in a foreign country where you have all sorts of unexpected extra difficulties.
I would say my masters so far has been pretty laid-back and (relatively for a physics degree...) not that demanding, but I still would barely be able to work part-time. If you're doing a PhD I'd say forget about working even part-time if it's more than 5-10 hours a week. Maaaaybe in the "research student" phase you could get away with it, depending what your supervisor thinks of it, whether he wants you to get down to the real work right away or not.