Under CAP371, and in any time band, the FDP is NOT legal unless a min rest period is thrown in there somewhere.
Assuming a report time of STD - 1hr and off duty is STA + 30mins, you'd be looking at a 12hr duty at least and that's assuming 30min turn time at ACE, LPA & ACE again, which you won't get.
Non starter mate and anyone who tries to tell you otherwise needs to go back to school.