Across:
8 Pool (PUDDLE) party (DUP = PUD-) upsets (= reversal indicator) older party (Democratic Left = -DL-) with ecstasy (-E) (PUDDLE),
9 Still under wraps (UNOPENED) in organisation (United Nations = UN-) with old (-O-) pair of writers (pen + ed = -PENED) (UNOPENED),
10 Cloud (MIST) covering William I’s temperament (covering ‘William I’s temperament’ = MIST),
11 The Tourists (TRAVELLERS) in time (T-) produced 5 down (Maurice -RAVEL- produced ‘Bolero’) for the French (the = -LE-) radio station, for starters (‘radio station’ for starters = -RS) (TRAVELLERS),
12 Some initial (‘some’ initial = S-) rumour (-TA-LE) about leading businessman (leading ‘businessman’ = -B-) (S TABLE) in firm (STABLE),
14 Stick (CL-ING) around county (Down) losing the head (D) (‘Down’ without ‘d’ = -OWN-) (CLOWNING) and acting the fool (CLOWNING),
15 Freud’s analysis (FREE ASSOCIATION) of Frank (frank/open = FREE) Bond (ASSOCIATION) (FREE ASSOCIATION),
18 Jokes (gags = G- -AGS) about young man (-LAD) getting tailor to finish (‘tailor’ to finish = -R-) (GLAD RAGS) party wear (GLAD RAGS),
20 Older sort (SENIOR) of address in Madrid (Senor = SEN-OR) protecting Third Reich (third letter of ‘Reich’ = -I-) (SENIOR),
22 One comical (one comical = ECONOMICAL) novel (= anagram indicator) never wastes a laugh presumably (ECONOMICAL),
24 Sides of herring instead (sides of ‘herring instead’ = HEAD) of complete salad? (HEAD of lettuce),
25 Putting one over on (BLUFFING) paramilitary organisation (Ulster Freedom Fighters = -UFF-) taken in by ostentatious regalia (BL-ING) (BLUFFING),
26 Set in motion removing items (‘set in motion’ removing ‘items’ = notion = NOTION) or that’s the impression (NOTION).
Down:
1 Stir up (stir up = PURIST) panic (= anagram indicator) – the traditional type that’s uncompromising (PURIST),
2 Cut out (EDIT) bad (= anagram indicator) diet (diet = EDIT),
3 Too nervous (RESTLESS) to relax (REST-) on the foreign (the = -LE-) ship (-SS) (RESTLESS),
4 Beastly type (PUMA) turns (= reversal indicator) up (up = PU-) to graduate (-MA) (PUMA),
5 Short jacket (BOLERO) in trunk (tree trunk = BOLE-) at end of corridor (end of ‘corridor’ = -R-) is old (-O) (BOLERO),
6 No gent will (no gent will = WELLINGTON) use (= anagram indicator) island capital (WELLINGTON = capital of New Zealand),
7 Verbally attack (TEAR INTO) head teacher (head ‘teacher’ = T-) for picking up on what’s said (-EAR) to teachers’ group (Irish National Teachers’ Organisation = INTO) (TEAR INTO),
13 Baker needs to handle this correctly to implement cuts (BREAD KNIFE) for a slice of the local cash (dough) (BREAD KNIFE),
14 Does away with (CHOPS) college (C-) dances (-HOPS) (CHOPS),
16 For checking who is there (ROLL CALL) for the presents? (presents / absents on ROLL CALL),
17 Audacious type (INSOLENT) in stolen (in stolen = INSOLENT) convertible (= anagram indicator),
19 Hand out pieces (ARM-) on one of The Stones (stone/pip = -PIT) (ARMPIT) from Oxter (oxter = ARMPIT),
21 You’d expect her to have something to say for herself (ORATOR) to one of the speakers (ORATOR),
23 Some public agencies (some ‘public agencies’ = CAGE) confining movement of beasty types (CAGE),
24 Bugbear (HATE) in heat (heat = HATE) wave? (= anagram indicator).