Across:
1 Covers-up direct order (cover-up ‘diRECT ORder’ = RECTOR) from minister (RECTOR),
4 Overseas parliamentary officials (SPEAKERS) employed by the musicians (SPEAKERS),
9 The boy cleaned up in Boston (restaurant ‘busboy’ cleaned up in US = -BUSED) after (= position indicator) American (A-) (ABUSED) was assaulted (ABUSED),
10 Pub (BAR-) set up by sommelier in The Cellar (wine -RACKS) (BARRACKS) in private quarters (private/army quarters = BARRACKS),
12 Romanians (Romanians) travelling (= anagram indicator) (Romanians = SAN MARINO) to small European republic (SAN MARINO),
13 Look for damages (-SUE) after (= positional indicator) minor relative (sis) loses the head (s) (‘sis’ without ‘s’ = IS-) (ISSUE) with the heirs (ISSUE),
14 Gathering intelligence around the earth (SPY SATELLITE) for a gent (a gent = agent = SPY) going to The Moon (The Moon is a natural SATELLITE of the earth) (SPY SATELLITE),
18 Pleading, flattering request (PRETTY PLEASE) to be mean-spirited (P-ETTY) about writing (from the 3Rs = -R-) by a muse? (a muse = amuse = PLEASE) (PRETTY PLEASE),
21 Undergo a sea change (ALTER) at top of the church (altar) state (= homophone indicator) (‘altar’ = ‘ALTER’),
22 One getting the worm (EARLY BIRD catches the worm) in the meal deal? (EARLY BIRD),
24 Our veg is (our veg is) cooked? (= anagram indicator) (our veg is = GRIEVOUS) Serious! (GRIEVOUS),
25 Writing (from the 3Rs = -R-) in new (= anagram indicator) scene (scene = SC-EEN) (SCREEN) relates to Partition (SCREEN),
26 Drunks (sots = S-OTS) around music venue (-HALL-) (SHALLOTS) will bring tears to your eyes (SHALLOTS),
27 Banks cash flow analysis (banks ‘CASh flow analySIS’ = CASSIS) of what’s consumed in France (CASSIS).
Down:
1 Consider in a new light (REASSESS) a fair amount of (half of) The Wire (half of ‘wiRE’ = RE-) and put a value on it (-ASSESS) (REASSESS),
2 Relishes (CHUTNEYS) church (CH-) tune (tune) showing off? (= anagram indicator) (tune = -UTNE-) Certainly (yes), when it’s empty! (e) (‘yes’ without ‘e’ = -YS) (CHUTNEYS),
3 Retiring (= reversal indicator) amidst Delaware population (amidst ‘delawARE POpulation’ = aerpo = OPERA) or Ring, for example? (Ring OPERA),
5 Soft (soft/quietly = PIANO) on footballers (PLAYERS) (PIANO PLAYERS) performing on a sessional basis perhaps (PIANO PLAYERS),
6 Opens 15 down (opens ‘air travel’ = AIR) for pilots (pilots) transporting (= anagram indicator) (pilots = PISTOL) (AIR PISTOL) one of the weapons (AIR PISTOL),
7 Too much (EXCESS) IN (in) XS (XS) on the radio? (= homophone indicator) (‘XS’ = ‘EXCESS’),
8 Part of the diagnosis terrified (part of the ‘diagnoSIS TERrified’ = SISTER) medical practitioner (nurse / SISTER),
11 Comes to nothing (BITES THE DUST) for most of them (most of ‘them’ = THE) after (= position indicator) getting mosquito stings (BITES) on what amounts to dead skin (DUST) (BITES THE DUST),
15 First class (AI-) retweet (RT = -R T-) from composer (Maurice Ravel = -RAVEL) (AIR TRAVEL) relates to the business dealings between JFK and Charles de Gaulle (AIR TRAVEL between JFK and Charles de Gaulle airports),
16 Senior ministers (CABINETS) protective of China perhaps? (China CABINETS),
17 Writer (-ED-) and director (-D-) consumed by factions (wings = W-INGS) (WEDDINGS) in the unions (WEDDINGS),
19 They’re tokens (BADGES) from first Boudin (first ‘Boudin’ = B-) and Degas (Degas = -ADGES) tour (= anagram indicator) (BADGES),
20 Garret (ATTIC-) is absent (-A) (ATTICA) from old part of Greece (ATTICA),
23 Unknown quantity (Y-) at college (University College Cork = -UCC-) lead with anthem (lead with ‘Anthem’ = -A) (YUCCA) from The Joshua Tree (Joshua tree = YUCCA).