Across:
8 Picks up (SENSES) germ from messengers (‘germ’ from ‘messengers’ = essens = SENSES),
9 Plays (D-RAMAS) outside foreign PM’s residence (Number 10 = -IO-) (DIORAMAS) producing a number of scenes that you’re likely to see in a museum (DIORAMAS),
10 Build (MAKE) goes around man-made lake (goes around ‘MAn-made laKE’ = MAKE),
11 A foreign (a = UN-) couple (ATTACH-) working on the paper (-ED) (UNATTACHED) not in The Union (UNATTACHED),
12 Names a (names a) model (= anagram indicator) (names a = SEAMAN) doing a job in The Caribbean (SEAMAN),
14 It’s airing Underwear, for instance (HOT PRESS) – it’s just released (HOT) by Pulp? (PRESS) (HOT PRESS),
15 Well, you’re not getting this (SICKNESS BENEFIT) for taking time off in a bad way (SICKNESS BENEFIT),
18 Stately homes (MANSIONS) on mains (on mains) supply (= anagram indicator) (on mains = MANSION-) with extreme outages (extreme ‘outageS’ = -S) (MANSIONS),
20 Minnesota is missing Tom (‘Minnesota’ is missing ‘Tom’ = innesa = INSANE) Batty (INSANE),
22 Who’s there (ATTENDANCE) in The Old Shoe (patten/clog), heading off (p)(‘patten’ without ‘p’ = ATTEN) for Charleston? (Charleston = -DANCE) (ATTENDANCE),
24 Clumsily saw (saw/chop = HACK) hairline crack at the edges (‘HAirline craCK’ at the edges = HACK),
25 Cannot (cannot = CON-ANT) work (= anagram indicator) across street (-ST-) (CONSTANT) in stable (stable/steady = CONSTANT),
26 Regalia from Anglo-American (‘Regalia’ from ‘Anglo-American’ = nomcan = CON MAN) fraudster (CON MAN).
Down:
1 Add a touch of sparkle (sparkle/bubbles = AERATE) as Judge (-RATE) Russell (AE-) is up first (= position indicator) (AERATE),
2 Dislikes abandoning kids (‘dislikes’ abandoning ‘kids’ = iles = ISLE) in Capri, for example (ISLE of Capri),
3 Distribution (ISSUANCE) of edition (edition/issue = ISSU-E) covering party in Africa (African National Congress = -ANC-) (ISSUANCE),
4 Finish off (l) ultimate (‘ideal’ without ‘l’ = IDEA) theory (IDEA),
5 Became unhinged (LOST IT), as there’s no peace in police state (there’s no ‘peace’ in ‘police state’ = olistt = LOST IT),
6 Those making amateurish films (CAMCORDERS) all about (= reverse all indicator) first season (first ‘Season’ = -S) on Red Rock (red rock) mostly (k) (‘red rock’ without ‘k’ = red roc = -CORDER-) at graduate (MA = -AM-) college (C-) (CAMCORDERS),
7 Irrigates (waters = WATERS-) a fair amount of (half of) Kill (half of ‘KIll’ = -KI) (WATERSKI) for sporty type overseas (WATERSKI),
13 Cracks (MAKES SENSE) in school (-S) after (= position indicator) 10 across (‘make’ = MAKE-) and most of 8 across (most of ‘senses’ = SENSE) (MAKES SENSE),
14 Hull’s (hulls = HUSKS) Hotel (H-) for my group (-US-) on weekend (‘weeK’ end = -K-) is small (-S) (HUSKS),
16 Nothing doing (INACTION) as short (n) legal proceeding (‘action’ = -ACTIO-) divides The Bar (the bar/ inn = IN-N) (INACTION),
17 Proof (EVIDENCE) endive (endive) salad (= anagram indicator) (endive = EVIDEN-) is cold (-C-) and gives energy (-E) (EVIDENCE),
19 Dated (OLD HAT) crazy (= anagram indicator) hot lad (hot lad = OLD HAT),
21 In the neighbourhood (near = NE-AR) around court (-CT-) (NECTAR) for a delicious drink (NECTAR),
23 Catches (NETS) reviews (= reversal indicator) of characters in The West End (in ‘the weST ENd’ = sten = NETS),
24 Let it be known indirectly (HINT) there are no wagons in Washington (no ‘wagons’ in ‘Washington’ = hint = HINT).