Cryptic crossword

ACROSS

1. Copper, within reason, shortened political meeting (6)

5. Left lump at the end of corn bread (7)

9. Confident old warrior, in retreat, ruptured one looking for riches (8,6)

11. Lie about fencing charge, admitting nothing (6)

12. Calm and quiet one, doused in fuel, moved around (8)

14. What a drinker might need to buy empty (4)

15. Each volunteer on board vessel identified people from one part of London (10)

18. Project leader feeling bitter about putting on a show (10)

19. Administrative official reduced size of hotel accommodation (4)

22. A judge transporting two learners back to court is generous (3,5)

24. See 7 Down

26. A hula tourists associated incorrectly with a state down under (5,9)

27. Faithful aunt worked in school (7)

28. Give up and come back? (6)

DOWN

2. Trapped pocket of gas turned rabbi blue (3,6)

3. Get mostly behind coal tax, say (6)

4. Only listened to one type of music (4)

5. Citrus fruit mild in taste in the extreme (10)

6. Large and heavy smoker catching cold in university (8)

7, 24 Across. Agreement about nonsensical UFO threat is very old (3,2,3,3)

8. Iron measuring rods and canes used to punish students (7)

10. Smooth leaf preserved in greasy stuff (4)

13. Extravagant speech, hard and unpleasant, should be reviewed (3,7)

16. Training and guidance disseminated over time (9)

17. Interrupted service fixed up on the broadcast fund raiser (8)

18. Applauds extra money given for working in public school (7)

20. Accept unlimited bets? (4)

21. Lots of fish in areas of shallow water (6)

23. Honour a former great racing car driver (5)

25. Move away from stairway (4)