Across:
   1. Compares to very small plants, we hear (6)
   4. Fashionable headgear on back-to-front in US (4)
   7. Some ask whether Ealing comedy is insubstantial (8)
   8. Give her a gun — invasion fleet sighted! (6)
  10. Cleaned brush on floor (8)
  13. Songs of trees around Gravesend (6)
  14. OK, get down around the river (7)
  15. Ex-students from Milan University initially (6)
  18. Meadow over the river (7)
  19. Order child to return rubbish (6)
  20. Return to tie up posh girl in space (7)
  25. Deserter gets the girl fairly (6)
  26. Obliged to have travelled around part of Hull? (8)
  27. Lord holds the French currency (6)
  28. Refraining from helping about 50 (8)
  29. Turn towards southern part of London (4)
  30. Strike out 100 from elected organisation (6)
Down:
   1. In oral, he identified the capital of Punjab (6)
   2. Bark one order near a dam (6)
   3. In Palestine, are rebels getting closer? (6)
   5. Rex lost article about bird (8)
   6. Now the French politician follows the man with the light (8)
   7. One set out for the Orient (4)
   9. Silas breaks down after one attack (6)
  11. Fish left in hat (7)
  12. “Bother!”, Princess burst out! (7)
  13. Ruler shows Harpo round a hospital (7)
  16. Loved trouble with communist (6)
  17. Game Mr Dawson follows comedy turn at Turks Head (8)
  18. White man has to step around jumping flea (8)
  21. Body of work contains revue on love (6)
  22. Able to move to US city (6)
  23. Respect last character leaving Madeira (6)
  24. Catch second horse (4)