Across:
1 What a shame (TOO BAD) digging up (= reverse indicator) leads in Dunedin, Auckland (leads/first letters in 'Dunedin Auckland' = da = -AD) and Wellington (boot = TOO B-) (TOO BAD),
4 Clip of (m) confidence trick (‘scam’ without ‘m’ = SCA-) by political party (Fianna Fáil = -FF-) is not new (-OLD) (SCAFFOLD) – it’s the one where the wrongdoers get suspended (execution platform = SCAFFOLD),
9 Save (RESCUE) Earl (-E) and Charlie (-C-) taken in by drug taker (user = RES-U-) giving everything up (= reverse all indicator) (RESCUE),
10 It’s about (RE-) stout (-PORTER) (REPORTER) employee synonymous with 20 down (‘papers’ synonymous/associated with REPORTER),
12 Time in prison for the local (STRETCH-) user (user) dumping a fair amount of (half) (half of ‘usER’ without ‘us’ = -ER) (STRETCHER) litter? (STRETCHER),
13 Slash (WOUND) or Sting? (WOUND),
14 Go on strike (MAKE A PROTEST) in March (MAKE A PROTEST),
18 Between ourselves, what’s said here only applies to the publishing business (OFF THE RECORD) in the classified section (OFF THE RECORD),
21 Some upsetting (= reverse indicator) parliamentary (some upsetting ‘parLIAMEntary’ = liame = EMAIL) form of communication (EMAIL),
22 Incites (incites) trouble (= anagram indicator) (incites = SCIENTI-) on street (-ST) (SCIENTIST) in Darwin (Charles Darwin = SCIENTIST),
24 Local wheeler-dealer (OPERATOR) or a trooper (a trooper) on the rampage (= anagram indicator) (a trooper = OPERATOR),
25 Sheepish type (MERINO) of medic (Medical Officer = M-O) touring Ireland (-ERIN-) (MERINO),
26 The job of the drug dealer (DISPENSE) is to give out (DISPENSE),
27 Unfinished (t) shelter (‘tent’ without ‘t’ = TEN-) causes offence to religious type (sin) up (= reversal indicator) (sin = -NIS) (TENNIS) for the game (TENNIS).
Down:
1 Meteor is (meteor is) out (= anagram indicator) (meteor is = TIRESOME) of the ordinary in a boring way (TIRESOME),
2 Position batsman takes perhaps (batsman facing bowler is “on strike” = ON STRIKE) is not working (ON STRIKE),
3 Mature (ADULT) soldier (lieutenant = -LT) follows (= position indicator) revolutionary (= reversal indicator) paramilitaries (Ulster Defence Association = UDA = ADU-) (ADULT),
5 What the average fan does (CLEARS THE AIR) removes uncertainty (CLEARS THE AIR),
6 What the consumers don’t want (FOOD WASTE) served in a restaurant? (FOOD) Outrageously – (= anagram indicator) a stew! (a stew = WASTE) (FOOD WASTE),
7 Decide not to join (OPT OUT) old (O-) heartless (a) Irishman (Pat) (‘pAt’ without ‘a’ = -PT) going on holiday (OUT) (OPT OUT),
8 It’s terrible (dire) in a roundabout way (= reverse indicator) (dire = -ERID-) in Germany (.de = D-E) (DERIDE) to mock (DERIDE),
11 Fundraisers on the High Street (CHARITY SHOPS) distributing (= anagram indicator) Cypriot’s hash (Cypriot’s hash = CHARITY SHOPS),
15 Partner (AFFILIATE) with others in academia (et al = -L-ATE) over institute (-I-) losing first (t) minor spat (tiff) (‘tiff’ without ‘t’ = iff = -FFI-)? Start arbitration (start ‘Arbitration’ = A-) and all take a step back! (= reverse all indicator)! (AFFILIATE),
16 South American (BOLIVIAN) overlooking (= reverse indicator) shortened (e) green (naïve) (‘naïve’ without ‘e’ = naiv = -VIAN) with the Italian (‘the’ Italian = il = -LI-) flower (River Ob = BO-) (BOLIVIAN),
17 Similar to those in 20 down (similar to ‘papers’ = EDITIONS) with issues (EDITIONS),
19 Finishes 18 across (finishes ‘off the record’ = RECORD) with memoir (RECORD),
20 What those in The Media make (PAPERS) of documentation (ID papers = PAPERS),
23 Bottle containing Genie certainly (bottle containing ‘geNIE CErtainly’ = NIECE) produced by family member (NIECE).