Across:
8 A (-A-) new (-N-) commercial (-AD-) welcomed by accountant (CA = C-A) (CANADA) providing a home for those in 15 across (providing a home for 'French Canadians' = CANADA),
9 Bad (bad) short (d) review (= reverse indicator) (‘bad’ without ‘d’ = ba = AB-) is typical (-NORMAL) (ABNORMAL) of eccentric (ABNORMAL),
10 Parcel (parcel of land = PLOT) for novice (learner = -L-) taken in by Kitty (P-OT) (PLOT),
11 Do a job in the city (do a job in The City = TRADE) on merger (merger = UNION) (TRADE UNION) with group of workers (TRADE UNION)
12 A (A-) heartless (i) organisation of people spying (CIA) (‘CIA’ without ‘I’ = -CA-) on agents (CIA) (ACACIA) leads to plant – a spiky type (ACACIA tree/plant has spikes),
14 More irritable (TETCHIER) row (row = tier = T-IER) goes over heads of even those (heads of ‘Even Those’ = -ET-) going to church (= -CH-) (TETCHIER),
15 Opens 22 across (opens ‘French maid’ = FRENCH) for American neighbours (CANADIANS) (FRENCH CANADIANS) – the ones with European ties (FRENCH CANADIANS),
18 What the foreman does (OVERSEES) when not in Ireland (overseas) it’s said (= homophone indicator) (‘overseas’ = OVERSEES),
20 Toffee (toffee) fudge? (= anagram indicator) (toffee = TEE OFF) Of course, that’ll get things going! (TEE OFF on golf course),
22 In a manner of speaking (FRENCH), a dim (a dim), criminal (= anagram indicator) (a dim = MAID) (FRENCH MAID), type in a saucy outfit (FRENCH MAID)
24 Leaves home (TREE) to interpreter with no printer (‘interpreter’ with no ‘printer’ = eter = TREE),
25 Watch guy that’s dealing (JEWELLER) with religious type (JEW-) losing the head (s) with figure in the market (seller) (‘seller’ without ‘s’ = -ELLER) (JEWELLER),
26 Article (the = TH-E) about motoring organisation (Royal Automobile Club = -RAC-) (THRACE) in old country (THRACE).
Down:
1 Fishy type (GAR-) of starters with lobsters in ceviche (starters with 'Lobsters In Ceviche' = -LIC) (GARLIC) that leaves a pungent aroma on the breath (GARLIC),
2 Flavour enhancer (SALT) found up (= reverse indicator) in Mount Lassen (found up in ‘mounT LASsen’ = tlas = SALT),
3 A hydrotherapeutic remedy perhaps (SALT BATH) found in 2 down (‘salt’ = SALT) and in England (BATH) (SALT BATH),
4 Sold out of Calvados (‘sold’ out of ‘Calvados’ = cava = CAVA) and Spanish wine (CAVA),
5 Trouble (UNREST) in organisation (UN-) getting time off (-REST) (UNREST),
6 Those with a nice heritage (Nice heritage = FRENCH) beat (WIN-) Marseille at The Centre (‘marsEille’ at The Centre = -E) (FRENCH WINE) in the red and white of Bordeaux? (FRENCH WINE)
7 In France, the old leader (NAPOLEON) on Lap One (on lap one = NAPOLEON) crashed? (= anagram indicator) (on lap one = NAPOLEON),
13 Came face to face with (CONFRONTED) inmate (CON-), a type of runner (-FRONT- runner) on drugs (ecstasy = -E-) and the first detained (first ‘Detained’ = -D) (CONFRONTED),
14 The pitfalls (TRAPS) of bringing up (= reverse indicator) small (-S) role for one in the abbey (role for one in The Abbey Theatre part = TRAP-) (TRAPS),
16 What’s found at the end of Davy Jones’ locker (RIVERBED) underneath the flower? (underneath the flower/river = RIVERBED),
17 Article (AN-) on good books (Old Testament = -OT-) consumed by current (tide = -TID-E) (ANTIDOTE) counter-agent? (ANTIDOTE),
19 No longer (EX-) healthy (-HALE) (EXHALE)? Take a breather! (EXHALE),
21 Type of toast (FRENCH toast) at the start of 6 down (at the start of ‘French wine’ = FRENCH),
23 Is open (AIRY) to leprechaun (fairy) heading off (f) (‘fairy’ without ‘f’ = AIRY),
24 Mentor’s son leaves (‘mentors’ ‘son’ leaves/without ‘son’ = metr = TERM) for an academic period (TERM).