Cryptic crossword No 3,289

Across

1. One displaces Tellurium from fossilised shellfish producing pungent gas (7)
2. Behemoth organisation kills man. Bunch of crooks! (3,3)
3. Draw back on new technology for police force (6)
4. Flower, river and tree shown in Ordnance Survey (7)
5. Apprentice in Leeds, perhaps, actually from Monmouthshire? (7)
6. Best location for a big wedding afloat? (5,5,5)
7. Lessons learnt by Eliza Doolittle? (6,9)
8. Wander over (4)
9. Drinks in front of opponents as mockery (6)
10. Chancer the very opposite of celebrities (4)
11. Get drugs, we hear, for very gymnastic swinging (7)
12. Liam with chance cycling breakdown (10)
13. Description of the noise made getting out of a cockpit by wartime RAF pilots? (3,3)
14. In short, Beau accomodates previous partner (10)

Down

1. Stem the flow of turbulent Thames with Barking moat (9)
2. Wear one's hat, for instance, around monarch in last ditch defence (9)
3. It's said a chap gets runs from tropical fruits (6)
4. Almost a little is a lot (5)
5. Arrive at slum with no warm water (3,2)
6. Evil comedy character's food (5,4)
7. Alter contract to have had the last word. (5)
8. Stuart casually makes an impression on people at college (8)
9. What gets in front, to get in front? (5)
10. Langour? No, get lost (3,5)
11. Kill time: it'll be a long winter (3,3)
12. The sort of film you wouldn't bother going out for (4,5)
13. Agreeing, by all accounts (9,2)
14. Controller will annoy. Cock! (6,5)