1 Left with some paper, and prepared to make a good case for it. (9)

 6 Not real spongy ground to you and me! (5)

 9 Turned to red at the turning. (7)

10 In Germany red, and in English a common article of the public building, perhaps. (7)

11, 13 and 27 down Heart-broken with a new twist concerning dishes, perhaps. (11)

12 Net. (6)

15 and 23 Pill? To keep fit, you might spend some time with it. (8,4)

16 Small landowners circle in 26. (6)

18 Tracks things like the Mona Lisa back to third parties in France. (6)

20 The speed with which disguised love goes to town. (8)

23 See 15 across

24 Sonny, could this be it? (6)

25 Set down a song, possibly, but not professionally. (3)

28 One might trail behind. (7)

29 Naturally, it’s heaviest. (7)

30 Players, with direction, might show class. (5)

31 Decals might be so hastened with determination. (7,2)
 

 1 Shakespearean trash, reputedly. (5)

 2 Didn’t stay up? Certain quitters may be. (7)

 3 The basis of a prodigal meal might go with so-called “piano legs.” (6,4)

 4 A variety of foothold? (It’s incorrectly told about certain government agents.) (8)

 5 Gore might write letters for her mate. (6)

 6 Small pieces that may be no good without a brace. (4)

 7 Material used in rigging hammocks. (7)

 8 Sailor’s girl follows one unaccompanied by lifelessness. (9)

14 No real news from here, possibly. (3,7)

15 Relating to the process by which material is built up into living matter. (9)

17 Does it represent extreme care to throw dice in perfect condition? (8)

19 Drinks when a member comes in, as one affirms. (7)

21 Does it take an unhealthy turn for some people? (3,4)

22 The sort of toys cowards get? (4-2)

26 Possible enemy country. (5)

27 See 11 across