Across:
8 Some craven Etonian (some ‘craVEN ETOnian’ = VENETO) taking in Venice (VENETO),
9 Refused to accept (RESISTED) desert is (desert is = RESISTED) contaminated (= anagram indicator),
10 To follow orders (OBEY), G-man leaves moneybag (‘G-man’ leaves ‘moneybag’ = oeyb = OBEY),
11 Identify (FINGER-) Spike (-NAIL) (FINGERNAIL) is a little nipper? (FINGERNAIL),
12 College (C-) in Haiti (Haiti = TAI -HI) adapted (= anagram indicator) (TAI CHI) exercises for the Orientals (TAI CHI),
14 Like a shot (FAST) that’s sold in gastro-pub (FOOD) (FAST FOOD) for dinner during Lent? (FAST FOOD),
15 Presumably, won’t be joining the guards (RESISTING ARREST) refusing to accept (RESISTING) 26 across (‘arrest’ = ARREST) (RESISTING ARREST),
18 Describes type of counselling (ADVISORY) or is Davy (or is Davy = ADVISORY) wrong? (= anagram indicator),
20 That man (-HE-) involved in conservative (Conservative/Tory = T-ORY) (THEORY) speculation (THEORY),
22 Incorporate (ASSIMILATE) Matisse, Ali (Matisse Ali = ASSIMILATE), Rocky? (= anagram indicator),
24 The foreign (the = LE-) paper (Financial Times = -FT) (LEFT) in Split (LEFT),
25 Con (CRIMINAL) is a lippy type (-RIM-), popular (-IN-) within California (CA = C-A-) law (-L) (CRIMINAL),
26 Slow down (ARREST) with Sartre (Sartre = ARREST) novel (= anagram indicator).
Down:
1 No Lent in East Berlin (no ‘Lent’ in ‘East Berlin’ = easbri = SERBIA) or in Central Europe (SERBIA),
2 Refuse to admit (DENY) what’s concealed by the downtrodden youths (what’s concealed by the ‘downtrodDEN Youths’ = DENY),
3 A local French cop (flic = -FLIC-) follows (= position indicator) criminal (CON-) for time (-T) (CONFLICT) in The Troubles (CONFLICT),
4 One of the boys (WREN boys) or one of the birds? (WREN),
5 Characters in Arkansas set sights (characters in ‘arkansAS SET Sights’ = ASSETS) on the balance sheet (ASSETS),
6 Taking advantage (USING) of (of = FO-) uplifting (= reversal indicator) religion (Roman Catholic = -RC-) and education (-E) (USING FORCE) is getting tougher (USING FORCE),
7 Peru’s oil (Peru’s oil = PERILOUS) production (= anagram indicator) is fraught with danger (PERILOUS),
13 Judge (CRITIC-) is (-IS-) getting manuscript (-MS) (CRITICISMS) with a number of commentaries (CRITICISMS),
14 Odd (FUNNY) entertainment (FUN-) on far side of prison (far side of ‘prisoN’ = - N-) yard (-Y) (FUNNY),
16 Consumers (END USERS) wind-up (END) those taking drugs (USERS) (END USERS),
17 Where you’ll find the lawyers (AT THE BAR) in a (A-) race (Isle of Man Tourist Trophy = TT race = -T T-) to rubbish (= anagram indicator) Rehab (Rehab = -HE BAR) (AT THE BAR),
19 Roman emperor (Nero = OR-EN-) retires (= reversal indicator) around island (-I -) near Troy (-T) (ORIENT) in the East (ORIENT),
21 Looking back (= reversal indicator), last insane (last ‘insanE’ = -E) surfer (surfer = refrus) has no right (r) (‘refrus’ minus ‘r’ = REFUS-) (REFUSE) to say no (REFUSE),
23 Fit for duty (ABLE) around (= reversal indicator) Italian island (Elba = ABLE),
24 Master (LORD) of using it up (= reversal indicator) in hydrolysis (in ‘hyDROLysis’ = drol = LORD).