Across:
8 Weekend (‘week’ end = - K -) in revolutionary (= anagram indicator) Cuba (Cuba = BAC- U-) playing the lead (‘playing’ the lead = -P) (BACK UP) or support? (BACK UP),
9 Retire (WITHDRAW) from ward with (ward with = WITHDRAW) doctor (= anagram indicator),
10 Offended (HURT) imp leaving in triumph (‘imp’ leaving in ‘triumph’ = truh = HURT),
11 Relishes (CONDIMENTS) chewing (= anagram indicator) second mint (second mint = CONDIMENTS),
12 It’s a comfort (RELIEF) to official (RE-F) holding on to story (-LIE-) (RELIEF),
14 Protects (SHELTERS) nervous (= anagram indicator) Ethel (Ethel = HELTE-) Roosevelt initially (‘Roosevelt’ initially = -R-) in ship (S-S) (SHELTERS),
15 Left, with no interest in coming back (MADE A CLEAN BREAK), for cooked up (MADE) avocado starter (‘avocado’ starter = A) with crisp (CLEAN) batter (BREAK) (MADE A CLEAN BREAK),
18 Fast, vile (fast, vile = FESTIVAL) criminal (= anagram indicator) in Fiesta (fiesta = FESTIVAL),
20 Bit of paper (TISSUE) with signatures doesn’t include Gran (‘signatures’ doesn’t include ‘Gran’ = situes = TISSUE),
22 This should be enough (SUFFICIENT) as it’s similar to 16 down? (‘adequate’ = SUFFICIENT),
24 Huge (VAST) gas stove goes out (‘gas stove’ ‘goes’ out/without ‘out’ = astv = VAST),
25 Regent is (regent is = STEERING) foolish (= anagram indicator) with one of the committees (STEERING committee),
26 Doesn’t take much to weigh down (OUNCES) old (O-) relatives (uncles) left (l) out (‘uncles’ without ‘l’ = -UNCES) (OUNCES).
Down:
1 Inherent quality of (NATURE of) sample covered up in a tureen (sample covered up ‘in a tureen’ = n a ture = NATURE),
2 Take off (SKIT) small-size (S-) jersey, shorts and socks (-KIT) (SKIT),
3 Writer (pen) briefly (n) (‘pen’ without ‘n’ = -PE-) consumed by sci-fi (sci-fi = S- CIFI-) compilation from the start (‘compilation’ from the start = -C) (SPECIFIC) is very particular (SPECIFIC),
4 Long-necked bird (SWAN) in boat coming from Botswana (‘boat’ coming from ‘Botswana’ = swan = SWAN),
5 Rear brakes (rear ‘brakes’ = S-) on bike (tricycle = trike = -TRIKE) (STRIKE) stop working (STRIKE),
6 Relative (Da) sets up (= reversal indicator) (Da = AD-) financial gambles (-VENTURES) (ADVENTURES) for those looking for escapism (ADVENTURES),
7 Turns up (= reversal indicator) broadcast (air = -RIA), etc., (etc = -CTE-) on an old boat (able-bodied seaman = ab = BA-) (BACTERIA) with bugs (BACTERIA),
13 Put a name on (IDENTIFIED) one of those singled out (IDENTIFIED),
14 Rob (rob = “steal” = “STEEL”) told (= homophone indicator) it’s very tough in construction (STEEL),
16 Good enough (ADEQUATE) for Bill (AD-) to get half of equity (half of ‘equity’ = -EQU-) before it gets swallowed (-ATE) (ADEQUATE),
17 The Script (NOTATION) starts off tour (starts ‘off tour’ = -OT-) in Germany, for one (N-ATION) (NOTATION),
19 Patsy (VICTIM) produced two little boys (Vic + Tim = VICTIM),
21 Concealed (UNSEEN) indentures doesn’t include DIRT (‘indentures’ doesn’t’ include ‘dirt’ = nenues = UNSEEN),
23 Broody Sultan produces them (broody Sultan = type of chicken produces EGGS) for horse (-GG-) in point-to-point (east + south = E-S) (EGGS),
24 Creepy sort (VINE) could be capable of sour grapes (VINE).