5 . On average, most of teeth chatter  (8)

 9 . Romney's party defends radical shift: that's where the attraction ends!  (4,4)

10. See 4 Down

11. M1's bridges still needing adjustment for heavy loads  (10)

12. Pretty reasonable  (4)

13. European waters flow the wrong way  (8)

16. One must be this to start to sizzle 24 tanned?  (6)

17. To sleep cuddling Romeo is divine  (6)

19. Wanting a name? I only love animated sailor  (5,3)

21. A greeting dog's overheard  (4)

22. Showing no thanks to peacekeepers taking charge in Gulf War  (10)

25. Be disgusting, just like this Scotsman  (6)

26. Favourite sofa? Short but sweet!  (8)

27. Case of one more losing the interest to tuck into rolled chop?  (8)

28. Felt tender parts from behind, finding painful growth  (6)

 2 . It could be too late for one engaged in jumping bail  (5)

 3 . Alternative to house rent rise?  (5)

 4/10 .        A man might, having had a spicy Indian  (7,6)

 5 . Opening and closing around middle of September, for harvest  (7)

 6 . Drummed up custom, halving odds for horse  (7)

 7 . Secure way to clue "open"?  (4-5)

 8 . Cultural divide in the sprawling metropolis  (9)

14. Cleavage depicted by mediocre painter, reportedly  (9)

15. Publication's unusual form of delivery?  (3,6)

18. Tailless horse, perhaps animal seen twice a year  (7)

19. The last character to be wearing tight angora fabric!  (7)

20. From country I governed twice with king deposed  (7)

23. Do this when caught in forward section of endangered aircraft  (5)

24. Going up to Cambridge maybe limits time with student  (5)