Across:
1 Official (FORMAL) characters in Gulf or Maldives (characters in 'gulF OR MALdives = FORMAL),
4 They’re witnessed in grave circumstances (FUNERALS) slowly making their way to a lifeless place of late (FUNERALS),
9 Works out (COUNTS) in cold (C-) on horses (mounts) starting off (m) (‘mounts’ without ‘m’ = -OUNTS) (COUNTS),
10 Problematic (= anagram indicator) satire (satire = AS IT -RE) about you and I (WE-) (AS IT WERE), in a manner of speaking (AS IT WERE),
12 27 across (‘prince’ = PRINCE-) gets to (-TO-) go to new (-N) (PRINCETON) Ivy League university (PRINCETON),
13 He’s leaving Sheridan (‘hes’ leaving ‘Sheridan’ = ridan = NADIR) at the lowest point (NADIR),
14 Competition (CONTEST-) at (-AT-) the start of invitational (the start of ‘Invitational’ = -I-) performing (-ON) (CONTESTATION) the process of rowing? (rowing/arguing = CONTESTATION),
18 Picture (SELF-PORTRAIT) what only you are capable of, you poser (SELF-PORTRAIT),
21 It’s stretching the truth to say (LYING) Bob has no part in lobbying (‘Bob’ has no part in ‘lobbying’ = lying = LYING),
22 The negative response (NO) to why it went wrong? (EXCUSES) (NO EXCUSES) Can’t complain about that! (NO EXCUSES),
24 Loud speaker’s (high frequency loudspeakers = TWEETERS) overly sentimental (TWEE-) period (term) cut short (m) (‘term’ without ‘m’ = -TER-) at school (-S) (TWEETERS),
25 Set up (= reverse indicator) very good (ok = KO-) State (= homophone indicator) plant (‘sow’ = ‘so’ = -SO-) even for Soave (even for/even letters for ‘sOaVe’ = ov) back (= reverse indicator) (ov = -VO) (KOSOVO) in The Balkans (KOSOVO),
26 Crafty (sly = S-LY) about mode of transport (-CAR-) going to Clare? (-CE-) (SCARCELY) Hardly! (SCARCELY),
27 Starter of nachos (starter of ‘Nachos’ = -N-) included in the cost one has to pay (price = PRI-CE) (PRINCE) in The Palace (PRINCE).
Down:
1 Confront (FACE) group of wolves (PACK) (FACE PACK) – it might save one's skin (FACE PACK),
2 Gatherings (REUNIONS) of neurons (neurons) damaged (= anagram indicator) (neurons = REUN-ONS) around centre of spine (centre of ‘spIne’ = -I-) (REUNIONS),
3 Cover-up somewhat ticks off (cover-up ‘somewhAT TICks off’ = ATTIC) one of those in The House (ATTIC),
5 Star (sun) losing the head (s) (‘sun’ without ‘s’ = UN-) is supported (-SANCTIONED) (UNSANCTIONED) and isn’t punished (UNSANCTIONED),
6 Auntie got (auntie got) drunk (= anagram indicator) (auntie got = EATING OUT) taking advantage of what’s in The Bistro (EATING OUT),
7 Advantages ignoring vast (‘advantages’ ignoring ‘vast’ = adnage = AGENDA) list of items (AGENDA),
8 Drink (SHERRY) the last of the Rieslings (last of the ‘rieslingS’ = S-) with German gentleman (-HERR-) getting tipsy at The Foundation (getting ‘tipsY’ at the foundation = -Y) (SHERRY),
11 A stiff Government ceremony organised in the dead centre (STATE FUNERAL) of Ireland (STATE) for most of those in 4 across (most of ‘funerals’ = FUNERAL) (STATE FUNERAL),
15 Endless (y) enthusiasm (‘energy’ without ‘y’ = ENERG-), etc. (ET-C), swallowing one (-I-) (ENERGETIC) type of bubbly (ENERGETIC),
16 Sounds like directions if you’re heading for Antrim (PASS DOWN) to give to your younger brother, for example (PASS DOWN),
17 Good books (Old Testament = OT-) on top (‘On’ top = -O-) Garda (-COP-) in southeast (-S-E) (OTOSCOPE) – the one investigating what’s going on along the canal (OTOSCOPE investigating the ear canal),
19 Odd (= anagram indicator) lapse (lapse = PLA-ES) over time (-T-) (PLATES) in China (PLATES),
20 Pictures (CINEMA) of workers (men) giving up (= reverse indicator) (men = -NEM-) – arrested by agents (CIA = CI-A) (CINEMA),
23 Thug leaves High Court (‘thug’ leaves ‘High Court’ = hicor = CHOIR) with those who are likely to sing (CHOIR).