Just to clarify on what a rude chap wrongly said earlier in the thread. Any UK A level equivalents are completely fine. I am currently through to the last stage with a BTEC National Diploma. I do also have an A level Mathematics. However, on the invite to the BA assessment they ask for proof of A levels including NAIRC OR, UCAS equivalency. So future applicants, if you have a BTEC National diploma which is the equivalent to BBC then don't hesitate to apply.
Hope this helps.