Across:
1 It’s most uncommon (RAREST) for artist (RA-) to relax (-REST) (RAREST),
4 Loud (forte = F-), wild (= anagram indicator) canine (canine = -INANCE-) Old Penny (-D) (FINANCED) paid for (FINANCED),
9 Sets of steps (LADDER) leading to large (L-) snake (-ADDER) (LADDER),
10 Closing time (DEADLINE) in lifeless (DEAD-) bar (-LINE) (DEADLINE),
12 Two women (Polly + Anna = POLLYANNA) – one is excessively optimistic (POLLYANNA),
13 It’s stretching the truth to say (LYING) Bob has no part in lobbying (‘Bob’ has no part in ‘lobbying’ = lying = LYING)
14 Dispute decision (ARGUE THE TOSS) to cross Swords (cross swords = ARGUE) to get article (THE) by Chuck (chuck = TOSS) (ARGUE THE TOSS),
18 Limp along, then stop (GRIND TO A HALT) by Mill (GRIND) Square (T- square) near Oxford (-O) with a (A) small railway station (HALT) (GRIND TO A HALT),
21 Puts on boots (puts on football boots = PLAYS) at the end of 1 down (end of ‘role play’ = PLAY-) finishing the chores (finishing the ‘choreS’ = -S) (PLAYS),
22 Pinkish (RED) local beef (local ‘beef’ = protest = GROUSE) (RED GROUSE) from game on the Moor? (moorland game bird = RED GROUSE),
24 Renders obsolete (OUTDATES) on holiday (OUT-) with potential mates (dates = -DATES) (OUTDATES),
25 Fish (PLAICE) for man leaving campanile (‘man’ leaving ‘campanile’ = cpaile = PLAICE),
26 What Robin is looking through (BIRD’S EYE) for new (= anagram indicator) bride? Yes! (bride yes = BIRD’S EYE),
27 The way things stand (AS IT IS), Asti is (Asti is) awful (= anagram indicator) (Asti is = AS IT IS).
Down:
1 Most of (s) those in 23 down (most of ‘roles’ = without ‘s’ = ROLE) with work in the abbey (PLAY) (ROLE PLAY) employ a therapeutic technique (ROLE PLAY),
2 Danger signs (RED FLAGS) for revolutionaries (RED -S) covering up slump (tire/exhaust = FLAG-) (RED FLAGS),
3 Poorly kept (SEEDY) view (SEE-) from heartless (uch) duchy (‘duchy’ without ‘uch’= -DY) (SEEDY),
5 Can’t hit a barn door (INEXACTITUDE) with stylish (IN-) precision (-EXACTITUDE), (INEXACTITUDE),
6 Genetic evidence (DNA) upsets (= reverse indicator) (DNA = AND-) gangster (Al Capone = -AL-) from America (America = USA = -US-A) taking over institute (-I-) (ANDALUSIA) in southern Spain (ANDALUSIA),
7 College (C-) ceremony (rite) ends early (e) (‘rite’ without ‘ e’ = -RIT-) for one (-I-) key (music key -C) (CRITIC) judge (CRITIC),
8 Director general (DG = D-G-) welcomes the German (‘the’ German = der) back (= reverse indicator) (der = -RED-) from Spain (-E) (DREDGE) to do some work on ocean liner? (to do some work on ocean liner/dredge the bottom = DREDGE),
11 You’ll find Hazel and Cherry maturing there? (hazel and cherry trees maturing IN THE NURSERY) Presumably, where one heard Old MacDonald had a farm! (heard Old MacDonald Had A Farm nursery rhyme IN THE NURSERY),
15 Serves up (= reverse indicator) most of (k) the light meal (‘snack’ without ‘k’ = snac = -CANS) certainly (sure = E-RUS-) including tea (-T-) (ETRUSCANS) for the old Italians (ETRUSCANS),
16 Lark (= anagram indicator) fails but (fails but = FABULIST) it’s an elaborate story! (FABULIST),
17 Turrets (Turrets) all over the place (= anagram indicator) (Turrets = UTT-RERS) around Spain (-E-) (UTTERERS) with speakers (UTTERERS),
19 Self-confidence (APLOMB) of a (A-) doctor (-MB-) behind (= position indicator) Middle East organisation (Palestine Liberation Organization = -PLO-) (APLOMB),
20 Write a (write a) novel (= anagram indicator) (write a = WAITER) working by a table (WAITER),
23 Parts (roles = ROLES) of parish records (rolls) on the radio (= homophone indicator) (‘rolls’ = ‘ROLES’).