Dering’s father, the eldest son of Sir Edward Dering, 7th bt., died, aged 25, in 1808, leaving the infant as heir apparent to the baronetcy and the Kent estates, which had been in the family for about 400 years. His mother remarried in 1810 another Kent landowner, Sir William Geary, 2nd bt. (1756-1825), of Oxenhoath, Member for the county, 1796-1806, 1812-1818. Dering came into his inheritance on the sudden death of his grandfather in 1811. (In a codicil to his will, dated 24 Apr. 1809, the baronet had provided £1,265 to clear his late son’s outstanding debts.) During his minority Dering’s affairs were managed by his great-uncle Cholmeley Dering† (1766-1836) of Regency Place, Brighton.
He had a conventional education and came of age in November 1828. Seven months later his mother put him up in absentia for Wexford, where her father Richard Nevill had alternated the nomination until his death in 1822 with the 2nd marquess of Ely. Lady Geary and her distant kinsman Henry Evans*, Nevill’s nominee, quarrelled with Ely who, denying the continued validity of the electoral pact, started his relative Sir Robert Wigram*. Dering was beaten at the poll, but his mother financed a petition. The committee, having decided that non-resident voters were ineligible, declared Dering duly elected on 15 Mar. 1830, and he took the oaths and his seat two days later.
Dering spoke at length against the reintroduced reform bill, 5 July. He claimed to be willing to consider any plan of practical improvement, but denounced the measure as ‘the forerunner of still greater changes’ and a ‘remedy’ which was ‘ten thousand times worse than any theoretical defects’. He voted against the second reading the following day and was in at least three of the obstructive minorities on the adjournment, 12 July. He made an unsuccessful plea for New Romney to be allowed to retain one seat by uniting it with Lydd and Old Romney, 26 July, and voted against the partial disfranchisement of Chippenham, 27 July. Thereafter his attendance seems to have fallen away. He was in the minority in favour of printing the Waterford petition for disarming the Irish yeomanry, 11 Aug. He voted against the passage of the reform bill, 21 Sept., and the second reading of the Scottish bill, 23 Sept., paired against the second reading of the revised reform bill, 17 Dec. 1831, divided against government on the Russian-Dutch loan, 26 Jan., and, with his last known vote in this period, opposed the third reading of the reform bill, 22 Mar. 1832.
Nothing came of speculation that he would stand for East Kent in 1832.
