Across:
8 Man of the cloth (TAILOR) showing off (= anagram indicator) Rialto (Rialto = TAILOR),
9 Criminal (= anagram indicator) dealers (dealers = REL-ASED) around Spain (-E-) (RELEASED) allowed to go free (RELEASED),
10 Drop out (OMIT) of Oxford (O-) and go to American university (-MIT) (OMIT),
11 A gloomy, dismal expression (LUGUBRIOUS) produced by Yank (yank/pull = LUG-) with brother (-BR-) on notice to pay debt (-IOU-) in America (US = -U-S) (LUGUBRIOUS),
12 Request the presence of (INVITE) popular (popular = IN-) vet (vet) working (= anagram indicator) (vet = -V-TE) across island (-I-) (INVITE),
14 Invoice (BILL-) is charged (-ION-) to Society (-S) (BILLIONS) keeping all the banks afloat presumably (BILLIONS),
15 Examples (REPRESENTATIVES) of agents (REPRESENTATIVES),
18 Writer (pen = PEN-) from play (= anagram indicator) using (using = -GUINS) (PENGUINS) The Birds (PENGUINS),
20 Panel discussion doesn’t include peninsula (‘panel discussion’ doesn’t include ‘peninsula’ = dscsio = DISCOS) with dance clubs (DISCOS),
22 Talk (CHAT-) by woman (-ELAINE) (CHATELAINE) – the female in charge of The House (CHATELAINE),
24 Hold (GRIP) on both sides of Greek ship (on both sides of ‘GReek shIP’ = GRIP),
25 Make it known (ANNOUNCE) to woman (ANN-) it doesn’t carry much weight (-OUNCE) (ANNOUNCE),
26 Penny (CO-IN) takes in party (Fianna Fáil = -FF-) (COFFIN) for one of those lifeless figures (COFFIN).
Down:
1 Whinge from signalmen (‘whinge’ from ‘signalmen who’ = salmno = SALMON) caught by one dropping a line (SALMON),
2 Accommodation (FLAT) concealed by rising (= reverse indicator) coastal fog (concealed by ‘coasTAL Fog’ = talf = FLAT),
3 They carry the messages (they carry the messages/shopping TROLLEYS) – the ones moving the theatregoers (theatregoers/patients on TROLLEYS),
4 Spike (spike = DRUG) takes honey off Greyhound (takes ‘honey’ off ‘Greyhound’ = grud = DRUG),
5 Young American woman (gal = G-AL) welcomes tips for lawyers or backers (tips for ‘Lawyers Or Backers’ = -LOB-) (GLOBAL) from all over the world (GLOBAL),
6 The ladies (the ladies’ toilets = FACILITIES) with foreign footballers (Football Association = FA-) from Long Beach and Glen Cove, for example (examples of cities = -CI-TIES), taking in Long Island (Long Island = -LI-) (FACILITIES),
7 Clip (SEQUENCE) of One Direction (South = S-), Queen (queen), Free (= anagram indicator) (queen = -EQUEN-) starting concert (starting ‘Concert’ = -C-) with energy (-E) (SEQUENCE),
13 System put in place to water down (IRRIGATION) European capital (capital of Latvia = -RIGA-) overwhelmed violently (= anagram indicator) in riot (in riot = IR-TION) (IRRIGATION),
14 Flips over (BENDS) bystander dropping tray (‘bystander’ dropping ‘tray’ = bsnde = BENDS),
16 Helen, Pat (Helen Pat), Rocky (= anagram indicator) (Helen Pat = ELEPHANT) and Jumbo (jumbo = ELEPHANT),
17 Auden (Auden = AUD-EN-) welcomes first person (-I-) from Clare (-CE) (AUDIENCE) to theatrical group (AUDIENCE),
19 Most (t) of the bias (slant) (‘slant’ without ‘t’ = -SLAN-) in papers (ID papers = I-D) (ISLAND) in Ireland, for example (ISLAND),
21 Seth leaves theorising (‘Seth’ leaves ‘theorising’ = oriing = ORIGIN) to Dawn? (ORIGIN),
23 Some upsetting (= reverse indicator) Thermopylae dictator (some ‘thermopylAE DIctator = aedi = IDEA) in thought (IDEA),
24 It might come as a surprise at Christmas (GIFT) to gas fitter shedding tears (‘gas fitter’ shedding ‘tears’ = gfit = GIFT).