Across:
1 Delegation dine out (‘delegation’ ‘dine’ out = elgato = GELATO) in the Italian parlour (GELATO),
4 It’s under control (OBEDIENT) in old (O-) part of the allotment (-BED-) on Irish domain (Irish domain = ie. = -IE-) by nectarine trees, for starters (‘nectarine trees’ for starters = -NT) (OBEDIENT),
9 Old one (old one = NOODLE) suspects (= anagram indicator) the local fool (NOODLE),
10 It’s got nothing to do with taking away (ADDITION) one of the tables (ADDITION tables),
12 It’s the origin (INCEPTION) of nice Pinot (nice Pinot = INCEPTION) served (= anagram indicator),
13 Some therapy emended (some ‘therapy emended’ = YEMEN) by Saudi Arabian neighbour (YEMEN),
14 Relentless, unreliable type (HABITUAL LIAR) of mannerism (HABIT-) by twin (dual) losing the head (d) (‘dual’ without ‘d’ = -UAL) at pop-up (= reversal indicator) bar (rail = LIAR) (HABITUAL LIAR),
18 Supports scoop of the summer (ICE CREAM CONE) – “Found in possession of 1 across” (found in possession of ‘gelato’ = ICE CREAM CONE),
21 Malnourished missing soldier? (‘malnourished’ missing ‘soldier’ = manuh = HUMAN) Corporal! (HUMAN body),
22 Suggest (RECOMMEND) taking “vista” out of inverted commas (taking ‘vista’ out of ‘inverted commas’ = neredcomm = RECOMMEND),
24 Crazy (= anagram indicator) maniac (maniac = MA-CIAN) entertains soldier (-GI-) (MAGICIAN) by pulling rabbits out of a hat (MAGICIAN),
25 Produced (= anagram indicator) a scent (a scent = STANCE) with attitude (STANCE),
26 Where to find one of those serving (find one of those serving on tennis court at BASELINE) in army headquarters? (BASE-) At the bar! (-LINE) (BASELINE),
27 Museum display of Socialist realism, for example (Red Art), set-up (= reverse indicator) (red art = TRADER) by dealer (TRADER).
Down:
1 Piece (GUN-) on The Clash (-FIGHT) (GUNFIGHT) leads to bitter exchange in the west (GUNFIGHT),
2 Dressing (oil = LIO-) up (= reversal indicator) for function at foundation (‘function’ at foundation = N) with junior reporters (CUBS) (LION CUBS) – presumably they have their pride (LION CUBS),
3 Head (T-IP) introduces university (University of Limerick = -UL-) (TULIP) to one of Lily’s family (TULIP),
5 What the devil is capable of (BAD INFLUENCE) is not right (BAD), for example (example/guide = INFLUENCE) (BAD INFLUENCE),
6 One of those bringing up the jerseys (DAIRY FARM) is playing (= anagram indicator) Friday (Friday = DAIRY F-) – prepare for a battle (arm = -ARM) (DAIRY FARM),
7 Show-off (= anagram indicator) in game (in game = ENIGMA) is a mystery to others (ENIGMA),
8 Fragment of overwritten anthology (fragment of “overwritten anthology” = TENANT) on the landlord’s books (TENANT),
11 You always get that after the death of a salesman, for instance (FINAL CURTAIN after Arthur Miller’s Death Of A Salesman), as there will be no show after this (FINAL CURTAIN),
15 Chile can’t (Chile can’t = TECHNICAL) disturb (= anagram indicator) what’s scientifically specialised (TECHNICAL),
16 Made a ruling (GOVERNED) – verged on (verged on = GOVERNED) ridiculous (= anagram indicator),
17 Teacher (HEAD-) with a number of gowns perhaps (-GEAR) (HEADGEAR) and mortarboards (HEADGEAR),
19 It’s not us (it’s them = THE M-) losing the head (j) with Biblical figure (‘Job’ without ‘j’ = -OB) (THE MOB) – it could be the wise guys (THE MOB),
20 Everything is backed up (= reverse all indicator) by leader’s generous attention (leaders ‘generous attention’ = ga = -AG-) welcomed by The House (semi = IM-ES) (IMAGES) Representatives (IMAGES),
23 Bit of Palermo tortellini (bit of “Palermo tortellini” = MOTOR) for the journey (MOTOR).