Across:
1 Work (LABOUR) for the scientists (LAB-) from old (-O-), old city (-UR) (LABOUR),
4 Brief visit to (STOP OVER) terminate (STOP) deliveries of bowlers? (6 delivers to an OVER for bowlers in cricket) (STOP OVER),
9 Give a seat to (VOTE IN) Victor (V-) and Oscar (-O-) close to Kurt (close/end to ‘kurT’ = -T-) – a German (‘a’ German = ein = -E IN) (VOTE IN),
10 Revolutionary (= reverse indicator) Sikhs (Sikhs) on the radio (= homophone indicator) (‘Sikhs’ = ‘seeks’ = SKEE-S) admitting it’s about (re = -ER-) time (-T-) (SKEETERS) the Americans find these local buzzers annoying (mosquitoes in America = SKEETERS),
12 Place (set = SE-T-) covering wild (= anagram indicator) green (green = -RENGE-) summit in (summit ‘In’ = -I) (SERENGETI) national park (SERENGETI),
13 Title holder (OWNER) – he comes out of nowhere (‘he’ comes out of ‘nowhere’ = nowre = OWNER),
14 One of those in charge of 3 down (LABOUR LEADER is in charge of ‘union’) and I across (‘labour’ = LABOUR) is ahead of the pack (LEADER) (LABOUR LEADER),
18 Where one looks to get an appointment (get a job/employment in LABOUR MARKET) for a fair amount of (half of) those in 14 across (half of ‘labour leader = LABOUR) and 27 across (‘market’ = MARKET) (LABOUR MARKET),
21 A large short-tailed Madagascan lemur (INDRI) protected by train driver (protected by ‘traIN DRIver’ = INDRI),
22 Leaving questions (Leaving Cert questions = EXAM PAPER) that could be best answered by those learning a lesson (EXAM PAPER),
24 Written justification (APOLOGIA) by American (A-) PA (-P-A) overseeing igloo (igloo) building (= anagram indicator) (igloo = -OLOGI-) (APOLOGIA),
25 Cope (MANAGE) with East German not getting rest (‘East German’ not getting/without ‘rest’ = eagman = MANAGE),
26 Former American president (George W. Bush = -BUSH-) taken in by a nomadic pygmy (Baka = BA-KA) (BABUSHKA) – an older relative of Putin’s, for example (Russian mother/grandmother = BABUSHKA),
27 Master key is missing – yes (‘master key’ is missing ‘yes’ = materk = MARKET), in a place of commercial activity (MARKET).
Down:
1 Built (= anagram indicator) villas (villas = LAVIS-L-) around hotel (-H) industry, ultimately (‘industrY’ ultimately = -Y) (LAVISHLY) in an extravagant manner (LAVISHLY),
2 Soup (= anagram indicator) – a broth (a broth = BATHRO-) from Belgium (-BE) (BATHROBE) – it will heat you up after a shower (BATHROBE)
3 Ulster (-NI-) approaching top out-half (top ‘Out-half’ = -O-) in a French (‘a’ French = un = U-N) (UNION) club (UNION),
5 Offer no resistance (TAKE IT) going to a (A-) school (-S) to study? (READ) (TAKE IT AS READ) Assume that’s not open to further discussion! (TAKE IT AS READ),
6 Mobile (= anagram indicator) phone (phone = PHENO-) for males (-MEN-) linked to a (-A) (PHENOMENA) number of those associated with The Prodigy and others (PHENOMENA)
7 Lot missing from anti-novel (‘lot’ missing from ‘anti-novel’ = aninve = VIENNA) from European capital (VIENNA),
8 A sorry (a sorry) criminal (= anagram indicator) (a sorry = ROSARY) picked up in the church when saying prayers (ROSARY),
11 Sense (FEEL) The House (HOME-) is (is) recalling (= reverse indicator) (is = -SI-) bank’s confidence trick? (banks ‘Confidence tricK’ = -CK) (FEEL HOMESICK) I miss the old digs, in a nostalgic way, living abroad! (FEEL HOMESICK),
15 It’s all agreed (UNANIMOUS) by a foreign (‘a’ foreign = UN-) ring (-O-) consumed by hostility (animus = -ANIM-US) (UNANIMOUS)
16 Miss (SKIP-) one of those who’ll give you a lift from the garage (-JACK) (SKIPJACK) or from the fish restaurant (SKIPJACK tuna),
17 The most severe (STARKEST) tests (tests) modified (= anagram indicator) (tests = ST- EST) around old flood defence (-ARK-) (STARKEST),
19 Tucker’s best partner (‘best bib and tucker’ = BI-B) welcomes Herbie (‘Herbie’ the love bug beetle = -CAR-) (BICARB) – a baker’s agent (BICARB),
20 Capsized (= reverse indicator) brothers (bros = -SORB) from dinghy start (‘Dinghy’ start = -D-) to head ashore (head ‘Ashore’ = A-) (ADSORB) or gather together on the surface (ADSORB),
23 Amuse oneself (PLAY-) on a (-A) (PLAYA) beach in Marbella (PLAYA).