Clarke Jervoise joined the Whig Club on 4 Apr. 1785 and was admitted to Brooks’s ten days later. On the death of Charles James Fox in 1806, he wrote to his nephew, ‘There was no one existing for whom I had a greater regard ... having from the earliest of days acted with him, and for near thirty years on all great public questions attended and voted with him ...’.
Clarke Jervoise, who seldom contributed to debate, voted with opposition on Oczakov, 12 Apr. 1791, and was listed favourable to repeal of the Test Act in Scotland the same month, but there is no sign of further attendance until 18 Feb. 1794 when he mustered for Fox’s convoy motion. Thereafter he frequently joined opposition minorities. There is no evidence that he had meanwhile been regarded as a likely recruit to government during the war with France and henceforward he opposed it, as well as the suspension of civil liberty at home. On 30 Nov. 1795 he presented the county petition against repressive measures.
He again voted with the Foxites in the first session of the Parliament of 1796, supporting reform on 26 May 1797. On 1 June he objected to George Rose declaring his interest in the loyalty loan bonus after the division had taken place. Thereafter he seceded with Fox, appearing only against the triple assessment, 4 Jan., the land tax redemption, 18 May, and the plight of Ireland, 14 and 22 June 1798. He next appeared in support of Sheridan’s motion for a separate peace, 1 Dec. 1800, and voted for Grey’s censure motion, 25 Mar. 1801. His only further minority vote during Addington’s ministry was on the imminent resumption of hostilities, 24 May 1803. He Voted against Pitt’s additional force bill, 8 June 1804, being locked out of the next division on the 11th.
Clarke Jervoise named the youngest of his three sons, Rev. Samuel Clarke, as heir to his borough interest, 30 Sept. 1807, having made him his residuary legatee. He died 5 Jan. 1808, ‘equalled by few, and surpassed by none’ in ‘public spirit, personal honour and gentlemanlike liberality’. His son Samuel obtained a baronetcy from Lord Liverpool in 1813.
