It's not allowed as only official sponsorship is allowed now. You need to have the money in an account in your name (could be joint with someone else) for 30 days prior to your application.
I've seen suggestions that the UK government is being tougher on students and checking that the course is of benefit to them rather than being an excuse to come to the UK to work. You may have to be able to provide good evidence of why you want to switch careers. Also bear in mind that even on an NVQ you are only allowed to work a maximum of 20 hours a week (including any work which is part of your course).