Across:
1 Profile (SHADOW) of constant companion in The Sun? (SHADOW),
4 EU dismissed by unsuitable (‘EU’ dismissed by ‘unsuitable’ = unsitabl = ISTANBUL) old capital (ISTANBUL),
9 Take turns (ROTATE) to judge (R-ATE) good books (Old Testament = -OT-) inside (ROTATE),
10 Launched (started = START-ED) around the back of Canaveral (the back of ‘canaveraL’ = -L-) (STARTLED) – surprised? (STARTLED),
12 Showed up (CAME) drug-free (CLEAN) (CAME CLEAN) – it’s what one did in confession (CAME CLEAN),
13 Jack (KNAVE) is one up from Number 10 (KNAVE),
14 1 across (‘shadow’ = SHADOW) is wrapping up (is BOXING) (SHADOW-BOXING) rehearsals for what’s going to happen in Ring (SHADOW-BOXING)
18 Modern (NEW-), empty (a) place (‘lay’ without ‘a’ = - LY) associated with (MARRIED) (NEWLY MARRIED) those who, until recently, had no mates (NEWLY MARRIED),
21 Switches (= reversal indicator) a (-A) precious stone (gem = -MEG-) for ring (O-) (OMEGA) – the last in a series (OMEGA),
22 Drunk (= anagram indicator) one claret (one claret = TOLERANCE) with patience (TOLERANCE),
24 Marine (NAUTICAL) is from Saint Lucia (‘is’ from ‘Saint Lucia’ = antlucia = NAUTICAL),
25 College (C-) in Haiti (Haiti = TAI -HI) adapted (= anagram indicator) (TAI CHI) exercises for the Orientals (TAI CHI),
26 The old poet’s (the old poets = BEATNIKS) family (kin) upset (= reversal indicator) (kin = -NIK-) in defeats (defeats/ beats = BEAT-S) (BEATNIKS),
27 Church (CH-) diocese (see = -EES-) backing (= reversal indicator) ecumenicalism from the start (‘Ecumenicalism’ from the start = -E) (CHEESE) in Gloucester (Gloucester CHEESE).
Down:
1 Unknown quantity (-Y-) in flying (= anagram indicator) saucers (saucers = S-RACUSE) (SYRACUSE) out from Mediterranean port (SYRACUSE),
2 Upstart (‘Up’ start = -U-) in Tuam (Tuam) crazy (= anagram indicator) (tuam = A-TUM-) with Nationalist (-N-) Revolutionary (= reversal indicator) foreign article (la = -AL) (AUTUMNAL) from the time of the fall in New England! (AUTUMNAL),
3 Tricky (= anagram indicator) topic (topic = OPTIC) for one on the bottle (OPTIC),
5 What a role model could do (SET AN EXAMPLE) for Irishman (Sean = SE- AN) over time (-T), when divorcee (EX-) has more than enough (-AMPLE) (SET AN EXAMPLE),
6 Freak rain (freak rain = AFRIKANER) storm (= anagram indicator) has Dutch origins (AFRIKANER),
7 Dance (BALL-) advertisement (-AD) (BALLAD) written by songwriter (BALLAD),
8 Sets of steps (LADDER) leading to large (L-) snake (-ADDER) (LADDER),
11 Father (Rev = VER-) taken aback (= reversal indicator) by leading (‘By’ leading = -B-) gangster (Al Capone = -AL) on charge (ATTACK) (VERBAL ATTACK) getting an earful? (an earful = VERBAL ATTACK),
15 Old (O-) crazy (= anagram indicator) painter (painter = -PERATI-N) welcomes Oscar (-O-) (-PERATI-N) (OPERATION) – the one regularly seen in The Theatre (OPERATION),
16 Knocks back (= reversal indicator) fizz (elan = NA-LE) – swallowing cold (-C-) quick drink (nip = PIN-) (PINNACLE) is always a highpoint (PINNACLE),
17 Broke (= anagram indicator) vase? Hide (vase hide = ADHESIVE) as this type of stuff sticks! (ADHESIVE),
19 Heads north of border (heads ‘North Of Border’ = -NOB) following (= position indicator) one of The Rings in the hospitality business (one of the ring in the hospitality business/kitchen = HOB-) (HOBNOB) to socialise (HOBNOB),
20 That’s one in the eye (NEBULA in the cornea) for The Cloud (NEBULA),
23 Dick gets off deckchair (‘Dick’ gets off ‘deckchair’ = echar = REACH) to stretch out (REACH).