French Aeroclubs are recreational members clubs where instructors draw no salary and put something back into aviation.
This may be letting the cat out of the box, but FYI, the way it works in France is you can either go and pay for your own FI rating (same as elsewhere), or you can negotiate with a club which will agree to finance your FI in exchange for committing to give 'x' amount of instruction hours at the club (typically 200-300) over a period of 'y' years (typically five). If you go that way (what's called the 'A list') you can do your course for about €3000, versus the €13000 it would cost you otherwise.
And btw, you do not need to have passed the CPL theory. The French have come up with their own examination which tests "knowledge at CPL level equivalent" or however it was phrased in the JARs, for the convenience of PPLs who wish to instruct.
AFAIK it is only one paper that you need passing instead of 7-8 for CPL.
The two caveats are: you need to pass a pre-admission test (flying and theory if not holding CPL/ATPL), and you need to speak French. To my knowledge, there is nothing stopping a UK-based club + instructor from applying to this scheme, btw.
Google the SEFA website if you need more info. Hope this helps.