Across:
8 Some initial (‘some’ initial = S-) rumour (-TA-LE) about leading businessman (leading ‘businessman’ = -B-) (STABLE) in firm (STABLE),
9 Is entitled (ELIGIBLE) to be a single chap (ELIGIBLE bachelor),
10 Shrewd (WISE) banks win and never lose (banks ‘win and never lose’ = WISE),
11 Close friend (intimate) briefly (e) (‘intimate’ without ‘e’ = INTIMAT-) is charged (-ION) (INTIMATION) for revelation (INTIMATION),
12 Daniel (Dan = N-DA) upset (= anagram indicator) over Eva (-EVA-) (NEVADA) in precious state? (NEVADA mines gold),
14 Concealed by applicant – a taster (concealed by ‘applicant a taster’ = CANTATAS) of the type of compositions composed by Bach, for one (CANTATAS),
15 Engineered a go-slow (DRAGGED ONE’S FEET) for what shifty type did with the speed (DRAGGED ONE’S FEET),
18 Local hooligan (yob) loses the head (y) (‘yob’ without ‘y’ = OB-) with one of those in court (-SERVER on tennis court) (OBSERVER) – presumably, it’s the witness? (OBSERVER),
20 Duck (-O-) found in chopped up (= anagram indicator) mince (mince = INC-ME) (INCOME) – the contents of a packet (INCOME is the contents of a pay packet),
22 Take exception to (DISAPPROVE) rewriting (= anagram indicator) Ovid’s paper (Ovid’s paper = DISAPPROVE),
24 Hope (WISH) of those coming off both sides of the Windrush (both sides of the ‘Windrush’ = WISH),
25 Tweak (FINE-TUNE) for dandy’s partner (FINE - and dandy) to air (-TUNE) (FINE-TUNE),
26 Stock (CATTLE) of cold (C-) beer (-A-LE) found outside the capital’s trendy taverns (capitals/heads ‘trendy taverns’ = -TT-) (CATTLE).
Down:
1 Priest (priest = STRIPE) serving (= anagram indicator) in bar (bar/line = STRIPE),
2 Qualified (ABLE) to remove art from Alberta (to remove “art” from “Alberta” = lbea = ABLE),
3 The roots (HERITAGE) of one (-I-) child’s game (-TAG-) wrapped up in the present (HER-E) (HERITAGE),
4 Fleet Street dismisses letters (‘Fleet Street’ dismisses ‘letters’ = ftee = FEET) from those filling someone else’s shoes perhaps (FEET),
5 Contract workers perhaps (HIT MEN) losing rag in nightmare (losing “rag” in “nightmare” = nihtme = HIT MEN),
6 Those in Sky (AIR TRAFFIC) to broadcast (AIR) a number of vehicles down the road (TRAFFIC) (AIR TRAFFIC),
7 Ration out (ALLOCATE) cook’s (cooks = anagram indicator) local tea (local tea = ALLOCATE),
13 American (A-) and Arabian (Arabian/horse = -GG-) agent (rep) nearly (p) (‘rep’ without ‘p’ = -RE-) takes theatre’s (-Gate’s = -GATES) (AGGREGATES) stuff on the road (AGGREGATES),
14 They’re capable of producing 14 across (CHOIR capable of producing ‘cantatas’) in part of the church (CHOIR),
16 Peaceful protest (sit in = -S IT IN) after (= positional indicator) Polish (polish = RUB-) (RUBS IT IN) adds insult to injury (RUBS IT IN),
17 Proof (EVIDENCE) of vice-president not taking trips (‘vice-president’ not taking ‘trips’ = viceeden = EVIDENCE),
19 Most of (t) the barrel (‘vat’ without ‘t’ = VA-) with port (-P-) is acidic (sour) when the top is taken off (s) (‘sour’ without ‘s’ = -OUR) (VAPOUR) and emits a gaseous substance in the air (VAPOUR),
21 Lost my (lost my = MOSTLY) potential (= anagram indicator), by and large (MOSTLY),
23 Some of the ghetto mentality (some of the ‘ghetto mentality’ = OMEN) can be read as a warning (OMEN),
24 Clever types (WITS) on the margins associated with wine and spirits (on the margins associated with ‘wine and spirits’ = WITS).