Fair enough. In that case, try
JAR-FCL 1, Appendix 1 to JAR-FCL 1.160 & 1.165(a)(4) - CPL Modular Course, paragraph 2(a):
Before commencing a CPL(A) modular course an applicant shall be the holder of a PPL(A) issued in accordance with ICAO Annex 1;
FFF
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(Edit to add - although I don't think it's relevant to your question - that the document I've linked to is Amendment 7 of JAR-FCL. The UK ANO currently recognises Amendment 5 as being the one that should be used in the UK. Except in certain random circumstances where the CAA have decided, without publishing it or telling anyone, that they're using Amendment 7 - but that's a different matter completely.)