Dunlop’s eldest brother inherited his maternal grandfather’s property of Craigie in 1770, and as his next brother Andrew renounced, it was Dunlop himself who acquired the paternal estate. His brother was the friend and patron of Robert Burns. As a professional soldier he served in America and India, being severely wounded in the right arm at Seringapatam, 1799. He afterwards served at home until 1810, when he went to the Peninsula and commanded a brigade in the fifth division and the division itself in 1811.
The Treasury were ‘hopeful’ of his support and by and large they obtained it. He voted in favour of Catholic relief, 2 Mar., 13 and 24 May 1813: not subsequently, though on 22 Apr. 1814 he voted for Morpeth’s motion critical of the Speaker’s anti-Catholic speech. He was in the minority against Christian missions to India, 22 June 1813. After voting with ministers on the civil list, 14 Apr. 1815, and on the army estimates, 6, 8 Mar. 1816, he was in the majority against continuing the property tax on 18 Mar. He was in the minority on the composition of the finance committee, 7 Feb., but voted against the opposition on the Admiralty salaries, 17, 25 Feb. 1817, and on the question of government spies, 11 Feb. 1818. He was, however, in favour of Holme Sumner’s attack on the additional grant to the Duke of Clarence, 15 Apr. 1818. He voted against Tierney’s censure motion of 18 May 1819, his only known vote in that Parliament. He does not appear to have contributed to debate. When threatened with a contest in 1820, he was backed by Lord Melville as ‘a friend of the present administration’, though Melville was informed that he was ‘uniformly considered in the county as a half Whig’, had not supported the six Acts and been absent both from Parliament and from the county meeting to address the Regent, 26 Nov. 1819, the holding of which he had opposed.