Across:
8 Endless (e) space for sitting down (settee) ('settee' without 'e' = SETTE-) with Rex (-R) (SETTER) – a hunting dog (SETTER),
9 God-like rule (THEARCHY) in church (-CH-) surrounded by earthy (earthy) ground (= anagram indicator) (earthy = THEAR-Y) (THEARCHY),
10 Plot (PLAN) over (= reverse indicator) in the Austrian Alps (in the ‘austriaN ALPs’ = nalp = PLAN),
11 Sneaking up on (SURPRISING) leaders stepping up revolutionary planning (leaders ‘Stepping Up Revolutionary Planning’ = SURP-) for Easter 1916 (-RISING) (SURPRISING),
12 Angelic figure (CHERUB) from revolutionary (CHE-) Russia (-RU-) starting to break (starting to ‘Break’ = -B) (CHERUB)
14 Travelling (= anagram indicator) near riot (near riot = ANTERIOR) nearer the front (ANTERIOR),
15 Irked (CROSS-) by 24 across (‘word’ = -WORD) and 8 across? (‘setter’ = SETTER) (CROSSWORD SETTER) That would be me! (CROSSWORD SETTER),
18 Chapels on rock summits (‘Chapels On Rock’ summits = COR-) near fashion centre (‘fasHion’ centre = -H-) in Mediterranean city (Nice = -NIC-E) (CORNICHE) running along the coast (CORNICHE road along coast)
20 Aftermath (RESULT) of Ulster (Ulster) Question? (= anagram indicator) (Ulster = RESULT),
22 Turns up (= reversal indicator), popular (in = -NI-) bird (emu = -UME-) caught (-C-) in Chantilly, for example (Chantilly lace = EC-AL) (ECUMENICAL), is used to promote unity (ECUMENICAL),
24 Promise (WORD) from world-weary missing lawyer (‘world-weary’ missing ‘lawyer’ = word = WORD),
25 County (DOWN-) Tipperary (T-) has an old city (-UR-) with new (-N) (DOWNTURN) economic problem (DOWNTURN)
26 For consumers, it’s a hot addition (CHILLI) to Catholic (C-) hospital (-H-) sick (-ILL-) unit (-I) (CHILLI).
Down:
1 Gangster (Al Capone = -AL-) in damp (wet = WE-T-) hotel (-H) (WEALTH) with means (WEALTH),
2 Shock (STUN) with content of fascist unorthodoxy (content of ‘fasciST UNorthodoxy’ = STUN)
3 Brag (crow = CRO-W) about ship (-SS-) from the heart of Cambodia (the heart of/ middle of ‘camBOdia’ = -BO-) (CROSSBOW) with old weapon (CROSSBOW),
4 Extremes of radioactive elements (extremes of ‘RAdioactive elemenTS’ = rats) up (= reverse indicator) (rats = STAR) in the sun (STAR),
5 Sad to say (REGRET), some overwater geraniums (some ‘overwaTER GERaniums’ = terger) coming up (= reverse indicator) (terger = REGRET),
6 Checkout what’s online (surf) reviewing (= reverse indicator) (surf = FRUS-) primarily trade (primarily ‘Trade’ = -T-) prices (-RATES) (FRUSTRATES) for hampers (FRUSTRATES),
7 Standing support (SHIN BONE) for Polish (polish/shine = SHIN -NE) around rising (= reverse indicator) river (River Ob = BO-) close to Pozna? (close/end to ‘poznaN’ = -N-) (SHIN BONE),
13 It’s about (RE-) Cologne (scent) reporting (= homophone indicator) (‘scent’ = ‘sent’ = -SENT-) workers (-MEN-) starting trouble (starting ‘Trouble’ = -T) (RESENTMENT) out of ill will (ill will = RESENTMENT),
14 Go along with (AGREE) a (A-) European (Greek) briefly (k) (‘Greek’ without ‘k’ = -GREE) (AGREE),
16 Swede’s (swedes = ROOT CROP) source (ROOT) from Trim (cut short/trim = CROP) (ROOT CROP),
17 Cruise (cruise) trip (= anagram indicator) (cruise = SUR-ICE) around outskirts of Panama Canal (outskirts of ‘Panama canaL’ = -PL-) (SURPLICE) with one of father’s outfit (SURPLICE),
19 The Count (CENSUS) wants to know if you still believe in God? (CENSUS).
21 See off yodellers (‘see’ off ‘yodellers’ = yodllr = LORDLY) in a grand way (LORDLY),
23 Criminals (CONS) on both sides concealing weapons (on both sides ‘COncealing weapoNS’ = CONS).
24 Taken in by Mafia women (taken in by ‘maFIA Women’ = fiaw) raising (= reverse indicator) (fiaw = WAIF) abandoned child (WAIF).