Symonds was returned unopposed for Hereford on the death of James Walwyn, like whom he enjoyed the support of the 11th Duke of Norfolk. He had been a member of the Whig Club since 15 Apr. 1788. In the House, where he was apparently a silent Member, he at once voted steadily with opposition until 25 Mar. 1801. Thereafter, in concert with his patron, he did not oppose Addington’s ministry and was listed ‘Prince’ on Pitt’s return to power in 1804. He steadily opposed Pitt, being listed ‘Fox and Grenville’ in September 1804 and ‘Opposition’ in July 1805. He supported the Grenville ministry, voting for their repeal of Pitt’s Additional Force Act, 30 Apr. 1806, and for Brand’s motion against their successors, 9 Apr. 1807.
Symonds, who took leave for bereavement on 1 Mar. 1808, did not appear in surviving minority lists for the next Parliament until 21 Feb. 1809, but voted steadily with opposition that session. Like his colleague Richard Philip Scudamore, he voted for the Whig ‘Mountain’s’ motions against abuses and ministerial corruption, 17 Apr., 11 May 1809, and, unlike him, against the militia completion bill, 2 May. The Whigs reckoned him among their adherents in March 1810. He voted for parliamentary reform, 21 May 1810, and was listed as a steward for the abortive constitutional reform meeting of 10 June 1811. But in August 1810 he was reported to be ‘dying’ and no vote of his is known before the dissolution after that against the Regency bill, 21 Jan. 1811, until on 27 Jan. 1812 he paired with the county Member Cotterell, who was then pressed by ministers to attend.
He reappeared, after sick leave, in May 1813, voting for Catholic relief and against a clause in the Admiralty registrars bill, but then disappeared until 1817. It was reported in April 1816 that he had been too ill to attend the House for two or three years and would resign at the dissolution, if not immediately.
In the contest for Hereford in 1818 he was at pains to deny reports of how he had been prepared to make way for John Somers Cocks: ‘I shall never carry you to the minister’s market’.
