Yorke was more interested in agricultural and antiquarian pursuits than in Parliament. In 1792 he was returned for Grantham by his brother-in-law, on the united Brownlow and Rutland interest, as a seat-warmer until his son Simon came of age. He supported Pitt’s administration, ‘although constitutional diffidence would not allow him to speak in the House’. He was, however, admired as a conversationalist. No vote of his is known in this period. After his retirement, he published at his own expense works on Welsh genealogy. His income was £7,000 p.a., ‘every shilling of which he did spend’. ‘Nimrod’ remembered him as ‘the worst horseman I ever saw in a saddle’. His letters to the 3rd Earl of Hardwicke, his second cousin, suggest that he was something of a valetudinarian.2Gent. Mag. (1804), i. 280; Add. 42072, f. 40. PRO 30/8/112, f. 170; A. N. Palmer, Old Parish of Wrexham, 241; C. J. Apperley, My Life and Times, 57, 59; Add. 35641, f. 374; 35642, ff. 203, 239; 35644, ff. 96, 111, 149, 230; 35686, f. 21.
After suffering ‘with spasms on his chest’, he died 19 Feb. 1804,3Add. 35644, f. 267. the embellisher of Erddig.