Across:
8 Spice (flavour) left out (l) ('flavour' without 'l' = FAVOUR) as an act of kindness (FAVOUR),
9 Hugh problem (HEADACHE) for that man (HE-) with crumbling (= anagram indicator) Dacha (Dacha = -ADACH-) close to steppe (close to/end of ‘steppE’ = -E) (HEADACHE),
10 An inspiration (MUSE) even to ombudsmen (even letters to ‘oMbUdSmEn’ = MUSE),
11 Ministers (FRONT BENCH) writing (from the 3Rs = -R-) in Times (Times font = F-ONT) about second (‘aBout’ second letter = -B-) and last chance (last ‘chancE’ = -E-) for politician finally (‘politiciaN’ finally = -N-) joining church (-CH) (FRONT BENCH),
12 Women (W-) opening bar (opening ‘Bar’ = -B-) in Asia (Asia) drunk (= anagram indicator) (Asia = -ASA-I) (WASABI) this pungent stuff as an accompaniment to raw fish (WASABI),
14 A fair amount of (half of) starch (half ‘staRCH’ = -RCH-) found in unfinished (l) meal (meal) (‘meal’ without ‘l’ = ME-A-) and not the sides (‘NoT’ the sides = -NT) (MERCHANT) produced by vendor (MERCHANT),
15 One of those giving private tuition (army DRILL INSTRUCTOR) in showing someone how to work on an oil rig (DRILL INSTRUCTOR),
18 Gatecrashes (BARGES IN) inns (BAR-S) around Germany (-G-), Spain (-E-) and up (= reversal indicator) North (NI = IN) (BARGES IN),
20 Fan letter? Far out (‘fan letter’ far out/without ‘far’ = nlette = NETTLE) and bound to sting! (NETTLE),
22 Tour by Queen (ROYAL VISIT) and Prince? (ROYAL) Go and see! (VISIT) (ROYAL VISIT),
24 and 25 across: They’re bound to manage classy figures (HEAD TEACHERS) for half of those in 9 across (half of ‘HEADache’ = HEAD) on wild (= anagram indicator) hectares (hectares = TEACHERS) (HEAD TEACHERS),
25 See 24 across
26 Wrongly take (NICK-) the Spanish (‘the’ Spanish = -EL) (NICKEL) coin (NICKEL).
Down:
1 Space (LACUNA) for the foreign ('the' foreign = LA-) copper (-CU-) joining new (-N-) agency (-A) (LACUNA),
2 Passed down tales (LORE) of French river (Loire) that’s empty (i) (‘loIre’ without ‘I’ = LORE),
3 The writing is on the wall (GRAFFITI) and it can be cutting (cutting = graft = GRAF-T-) about endless (x) drug taking locally (‘fiX’ without ‘x’ = -FI-) at institute (-I) (GRAFFITI),
4 Get lost (SHOO) in short (t) film (‘shoot’ without ‘t’ = SHOO),
5 Witty conversation (BANTER) and lies from East Berlin (‘lies’ from ‘East Berlin’ = eatbrn = BANTER),
6 Qualify (MAKE THE CUT) direction to one in The Theatre (MAKE THE CUT),
7 Really big African flower (big flower/river = THE CONGO river) company (CO-) behind (= position indicator) most of (m) them (‘them’ without ‘m’ = THE) Nerines growing on summits (‘Nerines Growing On’ summits = -NGO) (THE CONGO),
13 Party up north (Alliance Party = ALL-IANCE) embraces, for example (e.g. = -EG-) (ALLEGIANCE), loyalty to the crown, for instance (ALLEGIANCE),
14 Couple of family members (MA+SON = MASON) employed on site (MASON),
16 A (-A-) relative (-SON-) consumed by grass (reed = RE-ED) (REASONED) is well presented (REASONED),
17 Heard coming from a mobile (RINGTONE) in Waterford (RING-), in a manner of speaking (-TONE) (RINGTONE),
19 Votes (votes) lost (= anagram indicator) (votes = SOV-ET) around island (-I-) (SOVIET) by old council (old local, district or national council = SOVIET),
21 The Don, for example (LEADER), is crack (= anagram indicator) dealer (dealer = LEADER),
23 Work out (SUSS) what’s gone into in Jesus sandals (what’s gone into in ‘jeSUS Sandals’ = SUSS),
24 Clumsily saw (clumsily saw/chop = HACK) hairline crack at the edges (‘HAirline craCK’ at the edges = HACK).