Across:
1 Cite as evidence (ADDUCE) of Bill (AD-) meeting old Italian leader (-DUCE) (ADDUCE),
4 PS – casual (PS – casual = SCAPULAS) production (= anagram indicator) by The Blades? (shoulder blades = SCAPULAS),
9 By-product (RESULT) of sequel (RESULT),
10 Individual (ON-E-) covering fashion (fashion = -LOOK-) from centre of Paris (from centre of ‘Paris’ = -R) (ONLOOKER) for The Observer (ONLOOKER),
12 Declare (PRONOUNCE) to State? (state/say = PRONOUNCE),
13 Girl (-ANN-) in American state (New York = N-Y) (NANNY) is charged with safeguarding someone else’s issue (NANNY),
14 Ceremony for prospective partners (CIVIL SERVICE marriage) in Government administration (CIVIL SERVICE),
18 Politician with no local connections (CARPETBAGGER) to Persian, for example (Persian CARPET-), gets the sack (BAG-) – it’s a bit (m) of a bug? (germ) (‘germ’ without ‘m’ = -GER) (CARPETBAGGER),
21 Couple again (RETIE) to get rid of spam in spare time (remove ‘spam’ from ‘spare time’ = retie = RETIE),
22 Describes heavy metal (INORGANIC) to one (I-) music-maker (-ORGAN-) in Ulster (-N-I-) college (-C) (INORGANIC),
24 Instrument (MANDOLIN) is short (e) for a kitchen utensil (‘mandoline’ without ‘e’ = MANDOLIN),
25 Endless (p) music (‘rap’ without ‘p’ = -RA-) in restaurant (CA-Fé) (CARAFE) might be the choice of sommelier (CARAFE),
26 Room (SPACE) at the top bar (Attorney General = AG-) for middlemen (middle ‘men’ = -E) (SPACE AGE) is the epitome of what’s technologically advanced (SPACE AGE),
27 Flavour (SEASON) from small (S-) Irish bookseller (-EASON) (SEASON).
Down:
1 Broadcast (AIR) at the start of 26 across (‘space age’ = SPACE) (AIRSPACE) from the flight zone (AIRSPACE),
2 Detective’s (DIs = DIS-) work out (-SOLVE) (DISSOLVE) and wind down (DISSOLVE),
3 In The Abbey (CELL-) with old (-O) (CELLO) musical type (CELLO),
5 Crazy (= anagram indicator) conversation (conversation = CONSERVATION) for those looking to save Tomorrow’s World (CONSERVATION),
6 Raised from the ashes (Phoenix) without crossing (x) (‘Phoenix’ without ‘x’ = PHOENI-) intelligence agency (-CIA) (PHOENICIA) in old country (parts of Lebanon/Syria = PHOENICIA),
7 Fondness (LIKING) for fair amount of (half of) life (half of ‘life’ = LI-) in The Palace (-KING) (LIKING),
8 Waters down (SPRAYS) school (S-) petitions (-PRAYS) (SPRAYS),
11 Resourceful (ENTERPRISING) legal lodge (lodge a plea = ENTER- a plea) provides parking (-P -) for those on the way up (-RISING) (ENTERPRISING),
15 Will (will/bequeath = LEAVE) domestic (HOME) (LEAVE HOME) emigrate? (LEAVE HOME),
16 Dana sung (Dana sung = UGANDANS) arrangement (= anagram indicator) for the people from Africa (UGANDANS),
17 On the wagon (DRY) and drug free? (CLEAN) (DRY CLEAN) – what’s to launder? (DRY CLEAN),
19 Mops or (mops or = PROMOS) bundles (= anagram indicator) in trailers (PROMOS),
20 Curtailed part of (d) the stadium (“stand” without “d” = STAN-) with mid-sized (mid/centre of “sized” = -Z-) area (-A) (STANZA) for the linesman to workout (STANZA),
23 Drunk (= anagram indicator) lager (lager = GLARE) by the look of it, in a fierce way (GLARE).