Across:
8 A (A-) relative (-DA-) in the foreign army (-GI-) has nothing (-O) (ADAGI) to do with movement (ADAGIO),
9 Most of those in 24 across (most of ‘pigs’ = PIG) heard in the forum (heard in The Forum in Rome = LATIN) (PIG LATIN) saying “igpay Atinlay” for example (PIG LATIN is secret language/game: e.g., for a word starting with a consonant, move first letter to the end and then add ‘ay’),
10 Spike’s (spikes = PINS) in Trim (snip) head over heels (= reverse indicator) (snip = PINS),
11 List of chapters (CONT-ENTS) covering fashionable (-IN-) (CONTINENTS) large swathes such as North and South America (CONTINENTS),
12 In retrospect (= reversal indicator), more mature (riper = REP-IR) about a (-A-) (REPAIR) service (REPAIR),
14 Endless (f) foam (‘surf’ without ‘f’ = SUR-) on pints of stout (-ROUND) (SURROUND) in Ring (SURROUND),
15 Typical (REPRESENTATIVE-) school (-S) (REPRESENTATIVES) with a gents? (‘a gents’ = ‘agents’ = REPRESENTATIVES),
18 Old (-O-) Frenchman (Monsieur = -M-) consumed by the talk of Temple (talk of Jewish Temple = Hebrew = H-EBREW) (HOMEBREW) Bar offering, that’s made for personal consumption (HOMEBREW),
20 Winemakers dismissing Mike (‘winemakers’ dismissing ‘Mike’ = wnears = ANSWER) – and that’s supposed to be a solution? (ANSWER),
22 The Messenger (PIGEON-) has a green feature (a feature of a golf course green = -HOLE) (PIGEONHOLE) where you’d normally expect to find individual letters? (PIGEONHOLE),
24 No funeral in Persian Gulf (no ‘funeral’ in ‘Persian Gulf’ = psig= PIGS) for The Swine (PIGS),
25 Weekend (‘weeK’ end = K-) winter (winter = NITWE-R) break? (= anagram indicator) Get hold of one (-A-) (KNITWEAR) Aran jumper! (KNITWEAR),
26 Primate leaves prayer meeting (‘primate’ leaves ‘prayer meeting’ = yereng = ENERGY) with enthusiasm (ENERGY).
Down:
1 Counsel (ADVICE) to a (A-) Democratic (-D-) State (voice) not keeping order (o) (‘voice’ without ‘o’ = -VICE) (ADVICE),
2 Characters in some sense gaslighting (characters in some ‘senSE GAslighting’ = sega) all those retiring (= reverse indicator) (sega = AGES) for a very long time (AGES),
3 Clare (-CE-) behind (= positional indicator) criminal (CON-) retweets (-RTS) (CONCERTS) produced by those in the pits (CONCERTS),
4 The extremes of Newfoundland to Aleppo (extremes of ‘NEwfoundland to alepPO’ = nepo = OPEN) goes all the way back (= reverse indicator) (nepo = OPEN) to be honest? (OPEN),
5 Less attractive (UGLIER) great (-G-) fiction (-LIE-) found in old city (Ur = U-R) (UGLIER),
6 Classes (CATEGORIES) of accountant (Chartered Accountant = CA-), for example (e.g. = -EG-), welcomed by Conservatives (-T-ORIES) (CATEGORIES),
7 Train (= anagram indicator) cadets in (cadets in = DISTANCE) 100 metre dash (DISTANCE),
13 Concord’s (concords = AGREEMENTS) American (A-) workers (-MEN-) included in salutes (greets = -GREE-TS) (AGREEMENTS),
14 Lean or muscular type (SINEW) of new (= anagram indicator) wines (wines = SINEW),
16 A range of spirits (EMOTIONS) in one moist (one moist) cocktail (= anagram indicator) (one moist = EMOTIONS),
17 Triggered (AWAKENED) a late get-together (a late get-together = a wake = AWAKE-) for Edward (-NED) (AWAKENED),
19 Athlete (RUNNER) found up (= reverse indicator) in Burren nursing home (found up in ‘burREN NURsing home’ = rennur = RUNNER),
21 Employ (ENGAGE) part of forbidden gag explicitly (part of ‘forbiddEN GAG Explicitly’ = ENGAGE),
23 Characters in Basra orchestrated (characters in ‘baSRA Orchestrated’ = srao) Rising (= reverse indicator) (srao = OARS) with a series of rows (OARS),
24 Hull (PEEL) or Trim? (trim/pare = PEEL).