4  Extraordinary romance with 27 created 17 24  (7)

 9  Endlessly exploit and shock (4)

10 One relies on these investments? (4,6)

11/12       Malcontents need Ulster Unionists' instability for the essence of 17 24 (6,7)

13 I'm the sort that changed reduced working conditions (5,4)

15 Service worker lost heart (4)

16 See record return for run (4)

17/24       Voting in Roman election rigged to achieve this? (9,10)

21 Informal praise for the road to success? (3,2,2)

22 Biblical widow describes park cleaner (6)

24 See 17

25 Jump over container (4)

26 Remove clothing, for example, and in return find parts nudists have hidden! (7)

27 Starts to Conservative - Liberal electoral gerrymandering given support for 4 in 17 24  (5)

 1  Improve picture of outreach working without one  (7)

 2  African workers support prohibition (5)

 3  Double line stroke, one frequently found in tennis? (7)

 5  Demanding old flame leaves stand-in (6)

 6  Once and for all, disturbing banter's fulsome (9)

 7  From first to last, solicitors unfortunately remain too long. (7)

 8  High fliers' song by Lionel Richie's band (3,10)

14 Ape men try swinging for satisfaction (9)

16 Brake fails to start, it's confidential information. (3-4)

18 Unethical he isn't, deranged maybe (7)

19 I'm thinking, due to fix for wife (7)

20 Part of iliac or nearby membrane that can be transplanted (6)

23 It's not right disrupting exercise on this? (5)