Across:
1 Leaders of an unusual political alliance, in reality (leaders of ‘An Unusual Political Alliance In Reality’ = AU PAIR), a proponent of the nanny state perhaps (AU PAIR),
4 Member of Royal Irish Constabulary (OLD GUARD) in a faction that isn’t open to new ideas (OLD GUARD),
9 Taxpayers losing pay (‘taxpayers’ losing ‘pay’ = taxers = EXTRAS) and bonuses (EXTRAS),
10 Key players (PIANISTS) producing pastis in (pastis in) cocktail (= anagram indicator) (pastis in = PIANISTS),
12 Local suppliers (‘local’ / pub suppliers = BREWERIES) providing biers we’re (biers we’re) fabricating (= anagram indicator) (biers we’re = BREWERIES),
13 Designers out of evening dresses (‘designers’ out of ‘evening dresses’ = evens = EVENS) – what’s the chance of that? (EVENS),
14 Time (T-) traffic controller (-LIGHT) from Australia (Oz) retired (= reverse indicator) (Oz = ZO) – consumed by drink (wine = WI- -NE) (TWILIGHT ZONE) in an area of urban decay (TWILIGHT ZONE),
18 Raised someone’s spirits (-HEARTENED) following (= position indicator) detectives (DIs = DIS-) (DISHEARTENED) from Down (down = DISHEARTENED),
21 Wind up (CEASE) in college (C-) facility (-EASE) (CEASE),
22 In retrospect (= reversal indicator), managed (ran = NAR-) artist (-RA-) and odd (= anagram indicator) sort (sort = -TORS) (NARRATORS) of individuals doing voice-overs (NARRATORS),
24 It’s what 22 across did (‘narrators’ NARRATED) as told in the voice of one who knows the story (NARRATED),
25 Very good (DIVINE) papers (ID papers) review (= reverse indicator) (ID = DI-) Chardonnay producer, for one (-VINE) (DIVINE),
26 Conservative (C-) American city (New York = -NY-) in this Republican stronghold (Republic of Ireland/ROI = -RO-I-) bordering on sectarianism (bordering on ‘SectarianisM’ = -SM) (CRONYISM) showing favouritism to friends (CRONYISM),
27 Kitty (pot/fund) isn’t finished (d) (‘fund’ without ‘d’= FUN-) with Augustine (-GUS) (FUNGUS) from Portobello, for instance (Portobello mushroom = FUNGUS).
Down:
1 Travelling (= anagram indicator) by air, etc., (by air etc = ACERBITY) out of bitterness, in a manner of speaking (ACERBITY),
2 Pitiful (PATHETIC) Irishman (PAT-) with work (= anagram indicator) ethic (ethic = -HETIC) (PATHETIC),
3 Mad (IRATE) buccaneer (pirate) loses the head (p) (‘pirate’ loses ‘p’ = IRATE),
5 The French (‘the’ French = LA-) issue (issue) dismisses university (u) (‘issue’ dismisses ‘u’ = ISSE-) fellow (-F-) in old African country (Zaire = -Z-AIRE) (LAISSEZ-FAIRE) for a policy of non-interference (LAISSEZ-FAIRE),
6 Lure pet from putting green (lure ‘pet’ from ‘putting green’ = utinggren = GINGER NUT) with biscuit (GINGER NUT),
7 Solution (ANSWER) for getting Noel out of New Orleans (‘Noel’ out of ‘New Orleans’ = ewrans = ANSWER),
8 A lot missing from solid state (‘a lot’ missing from ‘solid state’ = sidste = DESIST) similar to 21 across (‘cease’ similar to DESIST),
11 Write (write) speech (= homophone indicator) (‘write’ = ‘right’ = RIGHT-) for worker (-HAND-) in hospital (-ER-) with endless (end ‘lesS’ = -S) (RIGHT-HANDERS) number of digs (digs/blows = RIGHT-HANDERS),
15 Planned route to be taken (ITINERARY) by one (I-) jockey- (= anagram indicator) -trainer (trainer = -TINERAR-) from yard (-Y) (ITINERARY),
16 Woman (ANN) and young man (boy) scratching head (b) (‘boy’ without ‘b’ = -OY-) in (-IN-) Government (-G) (ANNOYING) getting on someone’s nerves (ANNOYING),
17 Heading off (b) from Hull (body) (‘body’ without ‘b’ = -ODY-) on ship (-SS-) going from England (-E-) to America (-US) (ODYSSEUS) with Greek hero (ODYSSEUS),
19 Is of the view spectacular (SCENIC) pool table taken from police constable (‘pool table’ taken from ‘police constable’ = icecns = SCENIC),
20 Bob (HAIRDO) runs the committee (chair) without leader (c) (‘chair’ without ‘c’ = HAIR-) from party (-DO) (HAIRDO),
23 Stop living (die = -DIE-) in Australia (AU= A-U) (ADIEU) or I’m off! (ADIEU).