No requirement to have passed any theoretical examinations passes prior to commencing the flying training element as far as I can see. In my experience this has always been a much misunderstood point - particularly by TKIs!
CAP804 Section 4 Part A FCL.030 (Practical skill test) states: '(a) Before a skill test for the issue of a licence, rating or certificate is taken, the applicant shall have passed the required theoretical knowledge examination, except in the case of applicants undergoing a course of integrated flying training. In any case, the theoretical knowledge instruction shall always have been completed before the skills tests are taken'.
HW