Anson was defeated in a by-election at Great Yarmouth, where his family had some interest, in 1795. During this period he was serving in Jamaica. When he entered Parliament in 1806, it was as his elder brother’s successor at Lichfield, where the family interest commanded one seat, and he was unopposed in this period. Fox had just made his brother a viscount and he could be relied on to support the Grenville ministry. He divided with them for the repeal of Pitt’s Additional Force Act, 30 Apr. 1806. He was listed a staunch friend to the abolition of the slave trade. On 9 Apr. 1807 he voted for Brand’s motion following the dismissal of the ministry. He had not received a place from them, although his brother had applied to Earl Spencer for him, 24 July 1806:
He has a large and increasing family with but a very small income. I cannot express how much I should feel myself obliged to your lordship if you could appoint him to some situation of emolument within the sphere of your extensive patronage, which may not interfere with his military or parliamentary duties.
Spencer had nothing suitable to offer.
In the first two sessions of the Parliament of 1807 Anson supported opposition on the address, 26 June 1807, and on the Copenhagen expedition 3 Feb. 1808; was in Whitbread’s minority favouring peace negotiations, 29 Feb., Calcraft’s on the mutiny bill, 14 Mar. and opposed Patrick Duigenan appointment to the Irish privy council, 11 May. He further voted against the convention of Cintra, 21 Feb. 1809, before proceeding to the Peninsula. Between then and 1812 only one vote is known, for the censure of the Scheldt expedition, 30 Mar. 1810 (he was absent or paired on the same side on 5 Mar., but acknowledged the House’s thanks for his services at Talavera on 8 Mar.). The Whigs then regarded him as one of their ‘thick and thin’ supporters. He was at home in February 1812 when he missed Morpeth’s motion on Ireland, 4 Feb., but supported Turton’s censure motion, 27 Feb., and opposed the orders in council, 3 Mar. On 24 Apr. he supported Catholic relief.
Anson further distinguished himself as a cavalry officer in the battles of Salamanca and Vittoria.
