Vernon began in politics as a Tory, but by 1754 was a supporter of Administration. At the general election he was returned unopposed for Derby together with Lord Frederick Cavendish, strongly supported by the Duke of Devonshire; and in January 1756 told Lord George Cavendish that he ‘was resolved not to take part in anything of consequence’ until he knew Devonshire’s opinion.
the kind assurance I have formerly had from your Grace and Mr. Pelham, by whose advice I came into Parliament again with that view, and being recommended to his Majesty’s favour the very first opportunity ... I am sure the Duke of Devonshire will answer for my principles and pardon my saying that I think I have been of service, and may be of greater, as my interest in Derbyshire, Staffordshire, Cheshire, and Sussex are not inconsiderable, and his Majesty’s favour will strengthen them.
Newcastle wrote in his ‘Memorandums for the King’, 25 Mar. 1760:
He died 21 Aug. 1780.
