Across:
8 Graduate (MA = M-A) welcomes tips in making one sparkling (tips ‘In Making One Sparkling’ = -IMOS-) (MIMOSA) champagne cocktail (MIMOSA),
9 Opposed to (CONTRARY to) criminal (CON-) trial (TR-Y) involving a (-A-) third party (third ‘paRty’ = -R-) (CONTRARY),
10 Concealed by political leader (concealed by ‘politiCAL Leader’ = CALL) from Ring (CALL),
11 View (EYE-) from The Observer (-WITNESS) (EYEWITNESS) and The Spectator (EYEWITNESS),
12 Fool (nit) around (= reverse indicator) (nit = -TIN-) in foreign regiment (Special Air Service – nickname “The Regiment” = SAS = SA-S) (SATINS) with shiny materials (SATINS),
14 Doesn’t care for (DISLIKES) detective’s (Dis = DIS-) local digs? (local ‘digs’/likes = -LIKES) (DISLIKES),
15 Working out (TRAINING) at Dean’s place (COLLEGE) (TRAINING COLLEGE) in Templemore (TRAINING COLLEGE),
18 Park (P-) and area (-A-) managed (-RAN-) around (= reverse indicator) Number 10 (IO = -OI-) with a (-A) (PARANOIA) level of irrational mistrust (PARANOIA),
20 Given a job overseas (POSTED overseas) by crazy (= anagram indicator) despot (despot = POSTED),
22 The (the) Cure (= anagram indicator) (the = ETH-) is (-I-S) covering nothing (-O-) with musical instrument (piano) that’s not finished (o) (‘piano’ without ‘o’ = PIAN-) (ETHIOPIANS) by those living in Africa (ETHIOPIANS),
24 The shortest of distances (step) upsets (= reverse indicator) (step = PETS) the favourites (PETS),
25 County (DOWN-) players (-CAST) (DOWNCAST) in low spirits (DOWNCAST),
26 Identifying (NAMING) newbies and ministerial leaders (‘Newbies And Ministerial’ leaders = NAM-) in (-IN-) Government (-G) (NAMING).
Down:
1 Spies (CIA = CI-A) hiding rogue (rogue/ cad = -CAD-) (CICADA) bug (CICADA),
2 Logical proof bank’s backing (= reverse indicator) (‘LOgical proOF’ banks = loof = FOOL) clown (FOOL),
3 Irrigates (waters = WATERS-) a fair amount of (half of) Kill (half of ‘KIll’ = -KI) (WATERSKI) for sporty type overseas (WATERSKI),
4 Peter falls out of peach tree (‘Peter’ falls out of ‘peach tree’ = ache = ACHE) with sting (ACHE),
5 Auntie (auntie) broadcasted (= homophone indicator) (‘auntie’ = ‘anti’ = ANTI-) college (-C-) and school (-S) (ANTICS) pranks (ANTICS),
6 Code of ethics (PRINCIPLES) in clippers (in clippers) all at sea (= anagram indicator) (in clippers = PRINCIPLES),
7 Delivery of chicken (FRESH EGG) from chipper – in a healthy way (FRESH), it’s the early bird (EGG) (FRESH EGG),
13 Restrictions (limitations) starting off (l) (‘limitations’ without ‘i’ = IMIATATIONS) for Mocks (mocks = IMITATIONS),
14 Blind faith (DOGMA) in removing Renoir from reading room (removing ‘Renoir’ from ‘reading room’ = adgom = DOGMA),
16 Response (REACTION) to an erotic (an erotic) play (= anagram indicator) (an erotic = REACTION),
17 Is not in favour of (OPPOSING) sitting pretty perhaps (-POSING) after (= position indicator) relative (pop) loses the head (p) (‘pop’ without ‘p’ = OP-) (OPPOSING),
19 Characters in Corp. handpicked (characters in ‘cORP HANdpicked’ = ORPHAN) by one familiar with desertion relatively speaking (ORPHAN),
21 Writer (Ed = E-D) holds on to next (next) novel (= anagram indicator) (next = -XTEN-) (EXTEND) to make it longer (EXTEND),
23 A bit pretentious (ARTY) from political organisation (party) with no leader (p) (‘party’ without ‘p’ = ARTY),
24 Clip (t) of place (put) (‘put’ without ‘t’ = PU-) for foreign politician (-MP) (PUMP) with heart, for instance (heart = PUMP).