[…] if the Officers are allow’d to impose upon them, Under-Spur-leathers are always the Tyrants; a Government regulated by Laws, and Govern’d according to such Regulations, never willingly put it into the power of any Inferiour Officer to Tyrannize over his fellow Subjects.
Source: wiktionary
1711, Jonathan Swift, Letter to Esther Johnson dated 9 October, 1711, in Letters Written by the Late Jonathan Swift, London: C. Bathurst et al., 3rd edition, 1769, p. 61,
I have instructed an under-spur-leather to write so, that it is taken for mine.
Source: wiktionary
1816, Walter Scott, The Black Dwarf in Tales of my Landlord, Edinburgh: William Blackwood, Volume 1, Chapter 12, p. 242,
[…] I have opened house, not only for the gentry, but for the under-spur-leathers whom we must necessarily employ.
Source: wiktionary