1 Rather sudden warning concealing the iron cost, according to the ad. (5,6)

 9 and 10 Last words for such as Galahad, as one hears. (4,5)

11 A turkey perhaps used to be a body too small to be divided. (4)

12 Via Roma? Not exactly—rather northeast of it. (7)

13 Fooled someone with a perpendicular broad front. (7)

15 Supporter in an old king’s collection of school buildings. (8)

16 Swift creatures. (6)

18 For a clean sweep, see one who can tell you about it ahead of time! (6)

21 Sort of where the partridge was at Christmas? That’s clever! (8)

24 Butter portion that possibly offers protection. (7)

26 See 3 down

28 At this place she is possessive, to a point. (4)

29 Part of the day one follows with a beautiful and voluptuous woman. (5)

30 See 6 down

31 An unwitting soccer player might get such an admonition to hit the ball. (3,4,4)
 

 2 and 25 It might offer a solid squeeze, despite the source of power. (9,5)

 3 and 26 across Marathon story, as it happens. (7,7)

 4 Finds fault with poor horses. (4)

 5 Completely big-hearted plaything. (7)

 6 and 30 Some kidding around to measure this bird! (9)

 7 Alternatively, coming up to a couple of small establishments shows style. (6)

 8 Conducted inside, also made for the city. (6)

14 You have to take a lot of interest in this business, or it won’t exist. (5)

17 Damage done to a bent coin on a thing one might play. (9)

19 Cut and copied again? (6)

20 Most of the early surrounding could never be considered ethereal. (7)

22 Good fellow altogether proper like this? (7)

23 Arabian Nights’ Home Guard? (6)

25 See 2 down

27 The habit, in part, of one traditionally on her toes. (4)