Across:
8 Last of the cumin (last of the ‘cumin’ = -N-) in Raita (Raita = TIRA-A) mixture (= anagram indicator) (TIRANA) from European capital (TIRANA),
9 Was over the moon (SPACEMAN) sending up (= reversal indicator) celebrities (names = S-EMAN) taking in Cork (cap = -PAC-) (SPACEMAN),
10 Isolated without lost (‘isolated’ without ‘lost’ = iaed = AIDE) member of staff (AIDE),
11 Rocket Man’s outfits (SPACESUITS) used by more than one of those in 9 across (SPACESUITS used by more than on ‘spaceman’),
12 One of the hot ones (CHILLI) caught (C-) by bank (-HILL-) on island (-I) (CHILLI),
14 A drink before turning in (NIGHTCAP) crazy (= anagram indicator) thing (thing = NIGHT-) from Cork (cork/lid = -CAP) (NIGHTCAP),
15 Have a ball (PAINT THE TOWN RED) with revolutionary decree to the artists perhaps? (PAINT THE TOWN RED),
18 Admires (IDOLISES) one (I-) party (-DO-) on Isle (Isle = -LISE-) in conversation (= anagram indicator) with head of state (head of ‘state’ = -S) (IDOLISES),
20 Paper (THESIS) covers both sides of The Arms Crisis (covers both sides of “The Arms Crisis” = THESIS),
22 This is for the loungers (BEACH TOWEL) spread out by one enjoying The Sun (BEACH TOWEL),
24 100 (100 = Roman C-) -1 (-ONE) (CONE) = 99 (ice cream CONE),
25 Course of action (SCHEME-) for writing (from the 3Rs = -R-) introduction to screenplay (introduction to ‘screenplay’ = -S) (SCHEMERS) for those interested in plot (SCHEMERS),
26 Take one’s hat off (SALUTE) for military gesture (SALUTE).
Down:
1 Polish off (FINISH) fish in (fish in = FINISH) batter (= anagram indicator),
2 Versailles has no silver (‘Versailles’ has no ‘silver’ = ales = SALE) to auction (SALE),
3 Tad fishy (tad fishy = DAY SHIFT), criminal (= anagram indicator) never works nights (DAY SHIFT),
4 Haitians drop hint (‘Haitians’ drop ‘hint’ = aias = ASIA) it’s the biggest Mass on the globe! (biggest land mass = ASIA),
5 Troublemaker (BAD EGG) stinks out the co-op? (stinks out the coop = BAD EGG),
6 Unwillingness (RELUCTANCE) to trace uncle (trace uncle = RELUCTANCE) at sea (= anagram indicator),
7 The hectic life (FAST LANE) of one of those from The Road (FAST LANE),
13 Grounds (LAND-) for getting drunk locally? (-LOCKED) (LANDLOCKED) That doesn’t apply to anyone on the water! (LANDLOCKED),
14 Laid out deadlines (‘laid’ out ‘deadlines’ = ednes = NEEDS) and requirements (NEEDS),
16 Those in The House (AUDIENCE) listening to The Speaker (AUDIENCE),
17 Butchers’ (= anagram indicator) cuts also (cuts also = OUTCLASS) put others in the shade (OUTCLASS),
19 I, for one (Crosaire SETTER), condemned (= anagram indicator) retest (retest = SETTER),
21 Peaty coal (lignite) failed to start (l) (‘lignite’ without ‘l’ = IGNITE) fire (IGNITE),
23 Ferret removed from fresh water (‘ferret’ removed from ‘fresh water’ = shwa = WASH) is clean (WASH),
24 On the edges of commuter belt (on the edges of ‘commuter belt’ = COLT) going around Leopardstown (COLT horse).