1. The part of a boot or shoe above the sole.
2. A stimulating drug, esp. amphetamine.

Here in the US the second meaning is more common. And I think it fits the clue better: “Yet one may be at one’s lowest on them.”

Just for the sake of accuracy, in 16a you have ‘live’ in brackets instead of love.

A very enjoyable puzzle from Rufus which I actually finished for a change although my wife came up with landslide. I asked her if she could think of a word with the letters L_N_S_I__ and she came straight back with the correct answer. I was humbled and told her that nobody likes a smart a**e.

Favourites were PORTRAYAL, YVES, COUPLING, SPECTACLE, RELIEVE, PROVENDER and GESTURE. I also thought that 4d (YANKEES) was wonderfully concise.

Thanks Rufus.

I differ on this from Eileen and Gervase.

Although different components of the spectrum of meanings of ’cause’ merge into each other, the list given in Collins (below) shows the outer edges concerned here to be reasonably far apart.

1. a person, thing, event, state, or action that produces an effect
2. grounds for action; motive; justification
3. the ideals, etc., of a group or movement

‘Reasons’ in the clue fits clearly in differing senses as part of 1 and 2 – NB 1 does not in ordinary usage predicate the presence of mind or intention, nor the key terms of 3.

Some excellently misleading clues here: on 6a I spent some time trying to fit M (French Monsieur) into a three-letter word meaning grubby. Then I looked again and saw it staring me in the face.

I also read 8a as PUBLIC + A + N(ew).
Good clues also at 15, 1d and 14.

I liked this one a lot – perhaps because it is relatively light on the double defs. Particularly good cryptic defs at 25a and 5d, fun hidden clues at 6a and 27a, and 15a and 3d are clever.

And the bad news? SHIPMATES didn’t wow me, because ‘ship’ appears in both anagram fodder and solution, and, like others, I felt that CAUSES was barely cryptic.