Clues marked '*' are informed by 23 across, and '+' by 7 down

Across:
   1. Soldiers guarding gold, or hiding a man? One rich fellow thanks to design XC+! (7 6)
  10. Put on new play featuring popular lead (5)
  11. Gold fruit, new one which does its own thing (9)
  12. Something plumber put in and Ian ripped out (9)
  13. Leftover last bit of meal in scattered rice (5)
  14. Let hate upset 27's business (7)
  16. Harder to find in Oscar ceremony (7)
  18. Union purges mysteriously increase (7)
  20. Rubbish of his, an occupation of 1 (7)
  21. * Difficult position of Labor's union reps causing havoc (5)
  23. Sea Circus starts with its killer whale flipping ... there are some here only announced thus: * (9)
  25. Order to limit change to climate... most pointless? (9)
  26. * A legitimate, indeed believable indication proving you were somewhere else at the time? (5)
  27. Graduate with pissy sort of acid (say about 067.5), who smashed 100mL + (7 6)
Down:
   2. Takes action against awful ham pieces (9)
   3. * Really, artificial yarn or not? (5)
   4. Think up one bizarre enigma (7)
   5. Liberally recasts 8's occupation (7)
   6. They may be for those who are late and roam miles off course (9)
   7. Using some Latin, a tally of births? (5)
   8. Performed song - boring, total ham piece - but omitted F,G,H as player LX + (6 7)
   9. Christian con: a disaster, and out of date (13)
  15. There, rail travel gets to more of this world (9)
  17. Doctor, without hesitation, taking in calcium in mixture (9)
  19. "Flexible" lie cast out (7)
  20. Eel stewed with frog limb (7)
  22. * Round up my boys and dance (5)
  24. Gets a new platform (5)