Guardian 24375/Gordius – ance upon a time

This was hard work – with some answers really belonging in an advanced weekend puzzle — I found myself pulling out Chambers more than zero times, which is too many for a daily. I only fully understood the pair of 19 and 24 once I’d completed the puzzle — probably since I didn’t grow up in England in the 80s.

Across

1	INDIA – kind of hidden in “IN DIAmeter”. I assume INDIA really is 1500 miles in diameter at its widest point.
4	CHANCE,RY
8	TERMINAL CANCER – somewhat topical given the recent T5 debacle at Heathrow I suppose.
10	REGUL,ATE=rev(ETA, luger) – ETA’s our (Spanish) separatist movement.
12	I,MBALANCE=(can blame)*
17	A,DEPT – I suppose no need to hint at the abbrevation of department because…?
19	LAD(IE)S – yes, LADIES are people.
21	SEREN[e],DIP – yes I somehow knew that serendipity was derived from SERENDIP which was related to Ceylon somehow…
24	GREEN,HAM,COMMON – ref. the (women in the) 80’s movement to close down US nuclear bases on UK soil.
25	CARDITIS – groan. Inflammation of the heart.

Down

1	INTERMINABLE – def is “endless”. Not sure about the wordplay.
3	AMIEL=email* – ref. Conrad Black’s wife who is Lady Barbara… is “server” a good anagrind?
5	AN,CE – had to check this in Chambers. CE is our “establishment” and it’s how northerners might say “once”. At least once upon a time.
6	CANTAB,A,NK – Chambers says it’s a “strolling singer”.
7	REEST – I think this is an inversion that went wrong since else it’s an indirect anagram of steer for beef.
9	BOTTLE OPENER – first letter of BOTTLE is B…
13	LATTER END – and last letter of LATTER is R, though I would have preferred this to have been BITTER END given the beer ref.
20	DORS,A – hard clue: ref. Diana DORS (apparently a prewar sex symbol). And it’s Latin for “backs”.
22	ENO=rev(one),RM – another hard clue: RM for Royal Marine for “jolly”.
23	SHUT[e] – ref. Nevil SHUTE who wrote about Alice Springs and he’s missing an E which 13 defines.