Across:
1 One is up to one’s neck (CRAVAT) sorting (= anagram indicator) car (car = CRA-) tax (-VAT) (CRAVAT),
4 Sour (OFF-) port (-P-) is (-IS-) taken with a fair amount (half of) of Pâté (half of ‘Pâté’ = -TE) (OFF-PISTE) – that’s one slippery slope! (OFF-PISTE),
9 Runs daily (EDITOR) and rides out without us (‘rides out’ without ‘us’ = rideot = EDITOR),
10 You won’t get insurance for this (ACT OF GOD) in the flood (ACT OF GOD),
12 Qualification (AMENDMENT) for American (A-) repair (-MEND-) workers (-MEN-) at the end of employment (at the end of “employmenT” = -T) (AMENDMENT),
13 Is on the verge of making contact with (NEARS) new (N-) listeners (-EARS) (NEARS),
14 It’s almost (t) bright (‘intelligent’ without ‘t’ = INTELLIGEN-) going to Clare (-CE) (INTELLIGENCE) for news (INTELLIGENCE),
18 Is going nowhere (SOLID AS A ROCK) safe like Gibraltar (SOLID AS A ROCK),
21 Arabian (HORSE) removes museum from summer house (removes ‘museum’ from ‘summer house’ = rhose = HORSE),
22 Central (au) to faux (central to ‘fAUx’ = AU-) Ottoman (Ottoman = -TOMATON) novel (= anagram indicator) (AUTOMATON) by an unemotional type (AUTOMATON),
24 Confident and stylish type (DEBONAIR) making first appearance (debutante = DEB-) on the radio (on air = -ONAIR) (DEBONAIR),
25 Old bank (Anglo = ANGOL-) corrupted (= anagram indicator) a (-A) (ANGOLA) country in west Africa (ANGOLA),
26 Draw attention to (STRESS-) to 9 across, in short (‘editor’ = -ED) (STRESSED), desperate for a holiday (STRESSED),
27 Harry (HASSLE) lashes (lashes = HASSLE) out (= anagram indicator).
Down:
1 Make a comeback (= reversal indicator) – pose (sit = -TIS) for first album (first ‘Album’ = -A-) with Mel C (Mel C = CLEM-) (CLEMATIS) and Plant (CLEMATIS),
2 Upsets (AILMENTS) salt mine (salt mine = AILMENTS) engineer (= anagram indicator),
3 Give a wide berth to (AVOID) admiral heading (‘Admiral’ heading = A-) to Gulf (-VOID) (AVOID),
5 Wake up and smell the coffee? (FACE THE FACTS) It’s something you could make up perhaps (make up FACE) with article (THE) from encyclopaedia! (FACTS) (FACE THE FACTS),
6 Raised from the ashes (Phoenix) without crossing (x) (‘Phoenix’ without ‘x’ = PHOENI-) intelligence agency (-CIA) (PHOENICIA) in old country (parts of Lebanon/Syria = PHOENICIA),
7 Cue (SIGNAL) to Anglo-Americans to skip on camera (‘Anglo-Americans’ to skip ‘on camera’= aglins = SIGNAL),
8 Adam (ELDEST) and Ray from Steelyard (‘Ray’ from ‘steelyard’ = steeld = ELDEST),
11 Authentic local (LEGIT-) single (-I-) carpet (-MAT-) is (-IS-) engineered (-E) (LEGITIMATISE) to allow it conform with the standards (LEGITIMATISE),
15 Draw attention (Lo! = LO-) to circle (-O-) observed (-SE EN-) by detective (-DS) (LOOSE ENDS) with unfinished business (LOOSE ENDS),
16 Wedges (wedges/slices = PORTIONS) offered by the chipper? (PORTIONS),
17 Family (-KIN-) in shock (shock = S-CARE) (SKINCARE) use this to save face (SKINCARE),
19 Casts a shadow over (SHADES) Dante’s ending (‘DanteS’ ending = S-) in The Inferno (-HADES) (SHADES),
20 Kid (-RIB-) in Belgium (BE = B-E-) has recipe (-R) (BRIBER) for one producing sweetener (BRIBER),
23 Some characters maintain a momentum (some characters ‘maintAIN A Momentum’ = ainam) turning up (= reversal indicator) (ainam = MANIA) with wild enthusiasm (MANIA).