MFB's question was about base and line training, not the fATPL, JOC and MCC elements covered at the FTO, or the Type Rating conducted at the BA TRTO. The line training in the context MFB meant may well be around 44 weeks.
Neither the base nor line training is explicitly mentioned anywhere on the FPP website, although the website does imply that successful candidates will be employed with the company on completion of Type Rating (albeit only when and if vacancies exist on the line, so there could be a wait after finishing with the TRTO), and will be paid the starting salary from that date, prior to base or line training. Might be worth a call to BA to double-check that though -- and a brief report back here if you get an answer!