Cryptic crossword No 1,577

Across

1. Internal purge of rival, one without mercy in the end (5)
2. A man used a potty too much (2,7)
3. Decide about what you do? (7)
4. Elon's first social network to retweet piece-of-s*** bullies for money (7)
5. Blackbirds in China! (5)
6. Neon ball (3)
7. Might Edward really hit the bottom? (5)
8. "Princess and the Pee" makes a splash (3)
9. Large crater contributing to local derailment (7)
10. Tanner finally prints menu when bread evens out (6)
11. Island with dictator deserted on it is Elba? (5)
12. Needing no introduction: Fire and Fury (3)
13. See 6d
14. The very latest airhead to leave home of The Bears? (7)
15. See 1d
16. He brags like Gulliver addressing the Lilliputians? (3,6)
17. See 4d

Down

1. Swear to set webinars up (4,7)
2. Observe present and past in Bob (6)
3. Search engine's filled with every panda - they lessen resistence (4,8)
4. Paddington's skeleton delivered with essentials (4,5)
5. Nice one - the German is back, and England gets partially surrounded (5,5)
6. Perfect, or only good? (4,5)
7. See 3
8. Cockney had inspiring dream, left laughing (6)
9. See 20a
10. Punches way below the belt? (5)
11. 1? (10)
12. Head of essentially uncut hair (5)
13. Order pig stew for breakfast (8)
14. Negative Nancy orders tin openers (3)
15. Nightmarish beings announce an annoying printer feature? (6)
16. Lettuce head to glumly scoff served up ... (6)
17. ... bottomless salad is back, unfortunately! (4)
18. First sign of death row reversing part of sentence (4)
19. Cases and cases of tofu burritos (4)
20. What the snake says about a lack of respect? (4)