Cryptic crossword No 2,936

Across

1. Constable's work, perhaps, brings down crime for the most part (9)
2. Stopping for line adjoining Northern, head for Euston Road initially to get Central (5)
3. High-class UK Park flourishing with river passing (5)
4. Centrepiece of performance with rodent enthralled by green yarn? (9)
5. Hospital refuse cuts with urgency (5)
6. A little tense posting (3)
7. Throw out tariff restricting aid from the East (7)
8. Heralded princess's crown? (3)
9. Promotes bikes delivered (7)
10. Reform tactic – dropping Conservative's lead – elevated room (5)
11. Standing by Trafalgar Square, leaning – loyal tar at sea (8,7)
12. Dash of citrus with cored olive, mixed up and chopped (5)
13. Maiden caught coming out of noble's place (5)
14. African runner, first in Olympic final in Paris and three-time champion (7)
15. Gasbag sailor spun line – near eccentric! (7)

Down

1. Part in musical –Tootsie? (4)
2. Dice made from hard wood (4)
3. Wench topped and tailed perch, receiving small support (6)
4. State's first pair of Indian Tailed peacocks patrolling cape (8)
5. Rare garden redesigned? (10)
6. A great deal riding on new Champ (5)
7. A problem to solve every so often in squad workout (6)
8. Acting professional, Bill follows public relations, existing with spirit first to last (10)
9. American Dad's final words about work (4)
10. Bonnie's mate on the run in Scotland? (5)
11. Early signs from Neanderthal excavation record Scottish root? (4)
12. On the other side of Le Havre, fighting without Henry (8)
13. Good fortune received by Twist, before winter (8)
14. Conservative financial policy is sound – device undermines Green refusal (8)
15. Porridge served by bears inspired Roald Dahl originally (4)
16. Data nicked by worker, little tyke! (6)
17. One of the elders? (4)
18. Seize vehicle, apprehending old learner on initial lesson (6)