Across:
1 Quote (REPEAT) from Echo? (REPEAT),
4 Kept an eye on (OBSERVED) old (O-) backbencher, the first (‘Backbencher’ the first = -B-) to dish out (-SERVE-) dirt on leader (‘Dirt’ on leader = -D) (OBSERVED),
9 Profound (GRAVE-) opening lyrics (opening ‘Lyrics’ = -L) (GRAVEL) produced by The Stones (GRAVEL),
10 Most of (t) the component (‘part’ without ‘t’ = PAR-) from Oxford (-O-) stops working (-DIES) (PARODIES) with apes (apes/mimics = PARODIES),
12 Building (= anagram indicator) trades, etc., (trades etc = SCATTERED) here and there? (SCATTERED),
13 Turns up (= reverse indicator) Old Bob (‘old bob’ = shilling = -S) is a supporter of golf (tee = -EET-) and most top (‘Most’ top = M-) (MEETS) athletic events (MEETS),
14 Earn interest (earn interest) incredibly (= anagram indicator) (earn interest = ENTERTAINERS) from those putting on an act (ENTERTAINERS),
18 One would think this would be difficult to run (OBSTACLE RACE)? Irish (RACE) bar (OBSTACLE) opening (= positional indicator)! (OBSTACLE RACE),
21 Standard (USUAL) of university (-U-) in America (USA = US-A-) close to port (port/left = -L) (USUAL),
22 Twist (TURN-) – drinks for everybody (-ROUND) (TURNROUND) and the time it’ll take to get it (TURNROUND time or turnaround time),
24 Begin to understand (COTTON ON) criminal (con = C- ON) devouring good books (Old Testament = -OT-) by heavyweight (-TON) (COTTON ON),
25 Small (S-) company (Co = -CO-) car (model -T-) for going around Cloonfush (going around ‘CloonfusH’ = -CH) (SCOTCH), in spirit (SCOTCH),
26 Is under pressure (STRESSED) serving up (= reverse indicator) sweets, of course (sweets of course = desserts = STRESSED),
27 Vivacious wit (ESPRIT) of foreign (= anagram indicator) priest (priest = ESPRIT).
Down:
1 Boss (= anagram indicator) retires (retires = RE-ISTER) around Golf (-G-) (REGISTER) Lodge (lodge/submit = REGISTER),
2 Those in The Pod (PEAS-) lose the head (r) with angry outbursts (‘rants’ without ‘r’ = -ANTS) (PEASANTS) from old workers (PEASANTS),
3 Keeping an eye open (ALERT) for a typically drunk (ALE-) retweet (-RT) (ALERT),
5 Getting on (BOARDING) with Number 10 (CARD)? (BOARDING CARD) Essential to display this before The Rising! (BOARDING CARD),
6 Concerned with net sales (net/web sales = E-COMMERCE) of drugs sold online perhaps? (E-COMMERCE),
7 State’s (states = VOICES) immoral practices (V-ICES) surrounding order (-O-) (VOICES),
8 Stop (DESIST) a lot leaving solid state (‘a lot’ leaving ‘solid state’ = sidste = DESIST),
11 Part of Turkey (BREAST- of turkey), synonymous with golfer’s (golfer’s golf -STROKE) (BREASTSTROKE) discipline where there are water hazards perhaps (BREASTSTROKE),
15 Socialise (RUB ELBOWS) in Polish (polish/shine = RUB) joints (ELBOWS) (RUB ELBOWS),
16 One who knows the merit of what’s involved (VALUATOR) in detailed (e) price (value) (‘value’ without ‘e’ = VALU-) primarily for admission (primarily for ‘Admission’ = -A-) to The Hill (-TOR) (VALUATOR),
17 It appeals to assassin (HEADSHOT)? What one of those putting you in the picture wants perhaps! (HEADSHOT),
19 Those incapable of learning their lessons (DUNCES) from the corner boys (DUNCES),
20 The spread (BUTTER) of British (B-) state (-UTTER) (BUTTER),
23 Scare (scare) criminal (= anagram indicator) (scare = RACES) in tears (tears/rushes = RACES).