Cryptic crossword

ACROSS 1. Sound measure taken with bed to shift lice (7)

5. Port one may keep, as a grudge (7)

9. He shields the rotter who tangles with cop (9)

10. The highest happiness is to have some Chablis, seemingly (5)

11. The Keats version of Porterhouse (5)

12. Cheating the wind in weapon David used (9)

13. See-sawing with the Regent, tie was the outcome (9)

16. Girl following conservative leader in form (5)

17. He’s a good person to lay in a course (5)

18. Stuffing may come after mixing it (9)

20. Starts on a journey and puts it on display (4,5)

23. How to make oil go, dwelling in the cold (5)

25. He gets the pitch right for players (5)

26. Where audiences sit out, I’d aria to arrange (9)

27. Now, this is a gift (7)

28. What one makes at check-out may be a punishment (7) DOWN 1. What’s put down is turning up in the depot (7)

2. End of play makes the atmosphere stuffy (5)

3. Such speed may deprive the head of its support (9)

4. Old instruments let us play around with them (5) 5. A forerunner might brag in her situation (9)

6. Fanatical, the Right making an offer for it (5)

7. Have its start with trio in age of adaptation (9)

8. Leaves one’s post to organise the singers (7)

14. Fact of being next is EEC problem (9)

15. He tells about Ann to firm (9)

16. ‘Stinks’ is cry, the N being shifted (9)

17. One may alight here to put boss out (3-4)

19. Like a duet, it may be shown today and tomorrow (3-4) 21. Make false documents at the smithy (5)

22. Called to account for writing ‘DAH’ (3,2)

24. Great glare comes from it (5)