Dawkins succeeded his father as Member for Chippenham in 1784 and strengthened his interest in the borough by purchasing burgages. He was defeated in 1806, but was returned on petition and was again seated by the House after the election of 1807 when he obtained the same number of votes as another candidate. Following this contest, which had proved very expensive, Dawkins sold his property at Chippenham to John Maitland and in 1812 was returned on the recommendation of the Treasury at Hastings.
In his first Parliament Dawkins acted with opposition and joined the Whig Club, 3 Apr. 1787. In September 1788 Pitt made inquiries about the possibility of ousting him from his seat.
Dawkins looked to the Duke of Portland for a peerage for his father, but applications of 9 Oct. 1797 and 29 Dec. 1800 met with disappointment.
Dawkins rallied to Perceval’s ministry on the address, 23 Jan. 1810, and on the Scheldt questions, 26 Jan., 23 Feb. and 30 Mar. The Whigs were doubtful of him, under the name of ‘James Dickens’. He voted against parliamentary reform, 21 May 1810. On the Regency he appeared in the opposition majority, 1 Jan. 1811. He was in the government minority against Stuart Wortley’s motion, 21 May 1812. He opposed Catholic relief throughout in 1813. As a Treasury supporter after 1812, he voted with them on critical questions such as the Duke of Cumberland’s marriage grant, 29 June and 3 July 1815; the property tax, 18 Mar. 1816; the public revenue bill, 20 June 1816; the suspension of habeas corpus, 23 June 1817, and the Duke of Clarence’s establishment, 15 Apr. 1818. The Treasury included him in their dinner lists in 1818.
