Together, three unclued entries (two of two words) cryptically explain the three other unclued pairs. Solvers must highlight the single clued entry that could provide a further thematic example.

Across

1    The power to command text excited umpire (8)
6    Draws out English and Italian leaders (6)
13    Room at the top for Greek (5)
14    Maker of bargains, baronet meets King and Queen (8)
17    Long-suffering hospital case? (7)
18    I lead thunderous applause initially following organ suite (7)
19    Fluid measure requires more ether possibly (9)
23    Encroachment into Anchorage (6)
30    More than one building muscles on inside of legs regularly (9)
32    Fast cars stolen by Poles? (3,4)
33    Change travel to work (7)
35    Anaesthetises half the idiots (5)
36    Craziest drunken spree in front of one in trial (8)
37    Wing in grammar school used for festivals (5)
38    Plan he once devised for brain (10)
39    More frightening lake contained by returning engineers (6)
40    American muscle in the streets – a likely lot? (8)

Down

1    Mysterious Blaine holds the stage prior to landing out of reach (14)
2    Thailand adopts uplifting music app – crackers! (7)
3    Issue journalist with just the thing to get one tipsy (7)
4    Concerned with stuff under control (2,4)
7    Remove incumbent, other end spinning (8)
8    Engine possibly housed in motor with talent for beastly consumption (11)
9    Choose painter for daddy’s girl? (7)
12    Determined before fight (3-2)
15    Hear crude shout (4)
16    Perhaps pollen for hay fever sufferers is unrelenting, changing endlessly (11)
20    Sailor’s protecting unknown tyrant (4)
21    ‘Other woman’ losing initial interest (4)
22    Gaseous element results from iron being with lutetium and iron alloy (8)
25    One neat, tidy new-born (7)
27    Mould short dance to fit occasion (7)
28    Hospital department organised on time for admission? (7)
29    Rub fireplace (5)
30    Creep Miliband say, fronts GB Energy initially (4)

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A first prize of a £30 John Lewis voucher and two runners-up prizes of £20 vouchers for the first correct solutions opened on 25 May. Please scan or photograph entries and email them (including the crossword number in the subject field) to crosswords@spectator.co.uk, or post to: Crossword 2751, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.