Across:
8 Loud (GARISH) head barman (Attorney General = AG = GA-) serves up (= reverse indicator) type of whiskey (Irish) starting off (i) ('Irish' without 'I' = -RISH) (GARISH),
9 A (-A-) tenor (-T-) restrained by wireless (RADI-O-) recording introduction? (‘Recording’ introduction = -R) (RADIATOR) That’s bound to get heated! (RADIATOR),
10 Old Ruth (old/archaic ‘ruth’ = PITY) and Pierre-Édouard Dagoty taking sides (‘PIerre-édouard dagoTY’ taking sides = PITY),
11 Notices (spots = SPOT -S) around European (Czech) state (= homophone indicator) (‘Czech’ = ‘check’ = CHECK-) (SPOT CHECKS) for random examinations (SPOT CHECKS),
12 Casts a shadow over (SHADES) Dante’s ending (‘danteS’ ending = S-) from The Inferno (-HADES) (SHADES),
14 Heading to Canada (heading to ‘Canada’ = C-) and America (USA), going over (= reverse indicator) (USA = -ASU-) something like the ocean (salty) without first (s) (‘salty’ without ‘s’= -ALTY) (CASUALTY) requiring medical attention (CASUALTY),
15 A level of uneasiness (DISSATISFACTION) is (-IS-) behind (= position indicator) dispute primarily (‘Dispute’ primarily = D-) for compensation (-SATISFATION) (DISSATISFATION),
18 Stanley (STAN-) and Diana (-D-I-) going to school (National School = -NS) (STAND-INS) working as substitute teachers (STAND-INS),
20 The Yard (-Y) is after (= position indicator) gangster (DON-) from Kildare (-KE-) (DONKEY) for name of mule (DONKEY),
22 Teacher (Sir) loses the head (s) (‘sir’ without ‘s’ = IR-) with what’s admissible (-RELEVANT) (IRRELEVANT), as it’s beside the point (IRRELEVANT),
24 The ship’s captain in charge (BOSS) of armada dropping off ambassador (‘armada’ dropping of ‘ambassador’ = bsso = BOSS),
25 Divinity (HOLINESS) of gift missing out of lines of sight (‘gift’ missing out of ‘lines of sight’ = = linesosh = HOLINESS),
26 It’s exposed (OPENED) by old (O-) writer (-PEN-) employed by the paper (editor = -ED) (OPENED).
Down:
1 Lush (LAVISH) birch (birth/cane = LA-SH) hanging over sign (Victory/V sign = -V-), for one (-I-) (LAVISH),
2 Make shipshape (TIDY), as admiralty ignores alarm (‘admiralty’ ignores ‘alarm’ = dity = TIDY),
3 Ship (-S S-) close to Salé (close to ‘salE’ = -E-) consumed by Pirate’s strongbox (chest = CHES--T) (CHESS SET) containing pieces that will appeal to those who want a mate? (CHESS SET),
4 The Verve (verve/gusto = BRIO) in Brazilian capital (‘Brazilian’ capital = B-) city in South America? (-RIO) (BRIO),
5 Orders (EDICTS) copies of Proclamation! (EDICTS),
6 Become involved (TAKE PART IN) for time (T-) with a (-A-) family (kin = -K- IN) covering record (Extended-Play record = -E P-) with skill (-ART) (TAKE PART IN),
7 Prepare to empty the chamber (‘cock’ the gun = COCK-) for a (-A-) tawny headed (‘Tawny’ headed = -T-) couple of ducks (O+O = -OO) (COCKATOO) – one of which is a noisy bird (COCKATOO)
13 Detective’s (DIs = DIS-) in (-IN-) with that woman (-HER-) from IT (-IT) (DISINHERIT) – give her nothing (DISINHERIT),
14 The overheads (COSTS) of setting up (= reverse indicator) characters in populist society (characters in populiST SOCiety = stsoc = COSTS),
16 Notice Mr (notice Mr) Batty (= anagram indicator) (notice Mr = INTERCOM) employed in a telecommunications role (INTERCOM),
17 Tax cheat’s worst nightmare (AUDIT-) – getting charged? (-ION) (AUDITION) It’s an opportunity to test one’s ability at playing the eejit perhaps! (AUDITION),
19 Local diamonds (‘diamonds’ locally = ICE) sourced from China originally (TEA) (ICE TEA) by cool type during the summer (ICE TEA),
21 Posing less difficulty (EASIER) for loner from Sierra Leone (‘loner’ from ‘Sierra Leone’ = sierae = EASIER),
23 Pal leaves appeals (‘pal’ leaves ‘appeals’ = peas = APSE) in the section of the church (APSE),
24 Drink (BEER) for both sides on bench? Water! (sides on ‘BEnch watER’ = BEER).