I guess this is the correct place to mention this and it may have been mentioned before. At least it will serve as a reminder.
From the 1st of June Tesco clubcard vouchers can no longer be used for level 2 or 3 courses. You will still be able to use them for level 1 courses - I would imagine in an aim to convince you to continue studying higher levels.
I have heard you are able to use clubcard vouchers for level 2 and 3 if you pay for them before the 1st of June even if the course does not start for a long time.
The reason behind changing the scheme is probably due to a diminishing amount of funding available to the university. As an aside, there are some questions over the quality of the science courses but I believe these are being addressed.