Across:
8 It’s a symptom (SIGNAL) of gals in (gals in = SIGNAL) distress (= anagram indicator),
9 Jasper is not part of practical jokes (‘Jasper’ is not part of ‘practical jokes’ = cticalok = COCKTAIL) in Manhattan? (Manhattan COCKTAIL),
10 What the Coopers produced (casks) heading off (c) (‘casks’ without ‘c’ = ASKS) poses a question (ASKS),
11 Wave one’s magic wand (CAST A SPELL) from odd (= anagram indicator) pal’s castle (pals castle = CAST A SPELL),
12 Came (CAM-E-) across Park (-P-) and Ride initially (‘ride’ initially = -R) (CAMPER) looking for the pitch (CAMPER),
14 Tyrant (BULLY-) is popular (-IN-) leader of gang (leader of ‘gang’ = -G) (BULLYING) twisting someone’s arm (BULLYING),
15 As usual, you heard this already from spoofers (THE SAME OLD STORY), as nothing has changed (THE SAME OLD STORY),
18 Put in sets of (CLASSIFY) wild (= anagram indicator) salsify (salsify = -LASSIFY) behind (= position indicator) head of cabbage (head of ‘cabbage’ = C-) (CLASSIFY),
20 Frenchman (Monsieur = M-) gets to pull a face (pout = -P OUT) after (= position indicator) a (-A-) (MAP OUT) sketch (MAP OUT),
22 At the most (at the most = THE-MOSTAT), novel (= anagram indicator) includes writing (from the 3Rs = -R-) (THERMOSTAT) that runs hot and cold (THERMOSTAT),
24 Alec’s out of Muscatels (‘Alecs’ out of ‘Muscatels’ = must = MUST) and freshly pressed juice (MUST),
25 Stick (stick = CL-ING) around single (-I-) father (parish priest = -PP-) (CLIPPING) working in The Garden (CLIPPING),
26 Engineer (-E-) works (PLAN-T) outside (PLANET) with mercury (mercury = PLANET).
Down:
1 Hand (fist = FI -ST-) over key (music key -E-) to a (-A) (FIESTA) car (FIESTA),
2 Characters amidst gallant supporters (characters amidst ‘gallant supporters’ = ant s = ANTS) from The Hill (ANTS),
3 Pressure (P-) to elect (elect) headless (e) (‘elect’ without ‘e’ = -LECT-) type from The Bar (-RUM) (PLECTRUM), as will be useful for pulling a few strings perhaps (PLECTRUM),
4 Showcase who’s missing (‘showcase’ ‘whos’ missing = case = ACES) a great pair? (pair of ACES in poker),
5 Edison leaving out of cowardliness (‘Edison’ leaving out of ‘cowardliness’ = cwarls = SCRAWL) is hard to read (SCRAWL),
6 Presumably, this is how a dancer learns to dance (STEP BY STEP) and go up a flight to stage (STEP BY STEP),
7 First class (AI-) beer behind (‘beer’ behind = -R-) bar (-LINE-) has recipe (-R) (AIRLINER) that gives people a lift – a high one! (AIRLINER),
13 Tweet (POST-) and text (-SCRIPT) (POSTSCRIPT) as an afterthought (POSTSCRIPT),
14 Wild type (BLOWY) is feeling glum (-LOW-) after (= position indicator) bad start (‘bad’ start = B-) ending in bankruptcy (ending in ‘bankruptcy’ = -Y) (BLOWY),
16 This is bound to make things hot for anyone (HELL-) on a golf course (-HOLE) (HELLHOLE), as it’s an eyesore (HELLHOLE),
17 Rock sample perhaps (DEMO TAPE sample of rock band) is key (music key D-) to raised (= reversal indicator) volume (tome = -EMO T-) from parrot (-APE) (DEMO TAPE),
19 Important representative (ICONIC) of all the centres of Official Unionist cynicism (all the centres of ‘Official Unionist cynicism’ = ic+on+ic = ICONIC),
21 Side (ULSTER) producing poor (= anagram indicator) result (result = ULSTER),
23 Got (got = TOG-) off (= reversal indicator) school (S-) (TOGS) for the swim (TOGS),
24 Samuel ignores us (‘Samuel’ ignores ‘us’ = amel = MEAL) in the restaurant (MEAL).