Cock’s inherited his father’s founding interest in the Charing Cross banking firm of Biddulph and Cocks in 1804, together with two houses at the same location and £1,000.
He divided for Catholic relief, 6 Mar., and the duke of Clarence’s annuity, 16 Mar. 1827. He voted with Canning’s ministry for the grant to improve water communications in Canada, 12 June 1827. He divided against repeal of the Test Acts, 26 Feb., but for Catholic relief, 12 May 1828, and the Wellington ministry’s emancipation bill, 6, 30 Mar. 1829. He voted against the transfer of East Retford’s seats to Birmingham, 11 Feb., the enfranchisement of Birmingham, Leeds and Manchester, 23 Feb., and Jewish emancipation, 5 Apr., 17 May 1830. He divided against a reduction in judicial salaries, 7 July 1830. After his unopposed return at the general election that summer the ministry listed him among their ‘friends’, but he disappointed them by his absence from the crucial division on the civil list, 15 Nov. 1830. He voted against the second reading of the Grey ministry’s reform bill, 22 Mar., and for Gascoyne’s wrecking amendment, 19 Apr. 1831. At the ensuing dissolution he was replaced by his nephew Joseph Yorke.
Cocks’s involvement with his banking house, which was renowned for its fashionable and aristocratic clientele, and which had easily weathered the financial storm of 1825-6, had apparently ceased in about 1827.
