Your BA should be fine to get you onto a GDL as long as it is a bachelors degree.Your LLB should be fine to get you on to a GDL, I understand you haven't passed all the 7 core modules that would give you a qualifying law degree , or you have had more then 3 attempts at any core module. I would ask the institution you wish to study or GDL at if either your BA or LLB is fine to do the GDL.I know someone who did the London external LLB in Pakistan and then did his LPC at Nottingham Law School. He is now a qualified solicitor in immigration having just finished his training contract .