Stewart, who owed much to the 1st marquess of Abercorn, no doubt a distant cousin of his mother, retired as an Irish law officer in 1803 in exchange for a baronetcy and a pension. Returned for his native county on the Abercorn interest, 1802-6, and again, with the assistance of Lord Belmore, from 1812, he usually supported the Liverpool administration and, as an Orangeman, opposed Catholic relief.2 Add. 40298, f. 40; Extraordinary Red Bk. (1821), 222; PRO NI, Leslie mss MIC606/3/J/7/21/4; Hist. Irish Parl. vi. 343-4; HP Commons, 1790-1820, v. 275-6. In March 1820, when he signed requisitions for county meetings on George IV’s accession and on illicit distillation, he was again returned unopposed with his kinsman William Stewart of Killymoon.3 Belfast News Letter, 17, 28 Mar. 1820. He spoke against investigation of the Drogheda election, 25 May, and for his abortive Irish still fines bill, 7 June. Displaying his occasionally independent streak, he on 14 June divided for inquiry into Anglo-Irish trade, his only recorded vote that session. He was granted a month’s leave on urgent private business, 23 June 1820. He moved the resolution for a loyal address to the king at the Tyrone meeting, 24 Jan., but missed the division on ministers’ conduct towards Queen Caroline, 6 Feb. 1821.4 Ibid. 2 Feb. 1821. He voted against Catholic claims, 28 Feb. 1821, 30 Apr. 1822. He sided with ministers against Maberly’s resolution on the state of the revenue, 6 Mar., and repeal of the additional malt duty, 3 Apr., but was credited with a vote complaining of delays in the inquiry into the courts of justice, 9 May 1821. He voted against more extensive tax reductions to relieve distress, 11 Feb., but cast a wayward vote to permit the grinding and export as flour of bonded corn, 10 June 1822.
Remarking that ‘many of the most loyal inhabitants of that country felt sore’ regarding the legal proceedings in Ireland against the Orange rioters, Stewart hinted that he would raise the matter again, 18 Feb. 1823.5 The Times, 19 Feb. 1823. According to Thomas Creevey*, who called him ‘a damned fool withal as I ever beheld’, he was to have introduced a definitive motion on the 24th, when, however, he merely repeated his opposition to the actions of William Plunket, the Irish attorney-general.6 Creevey mss, Creevey to Miss Ord, 21 Feb. 1823. He apparently missed the division on this issue, 22 Apr., although he was involved in the questioning of witnesses, 5-7 May. He voted against repealing £2,000,000 of taxes, 3 Mar., and for the grant for Irish churches and glebe houses, 11 Apr. He presented anti-Catholic petitions from Killyman, 16 Apr., and Tyrone, 17 Apr., and intervened on the Irish tithes bill, 16 May, 16 (when he divided against its committal), 18 June.7 The Times, 17, 18 Apr., 19 June 1823. He voted against reform of the Scottish representative system, 2 June, but to condemn the conduct of the lord advocate in the Borthwick case, 3 June 1823. No trace of parliamentary activity has been found during the 1824 session. He voted for the Irish unlawful societies bill, 15 Feb., and, having brought up petitions for suppression of the Catholic Association from Ardstraw and Tyrone, 17, 23 Feb., he divided for the last time against Catholic relief, 1 Mar. 1825.8 Ibid. 18, 24 Feb. 1825. Later that year, ‘being enfeebled by long and severe indisposition’, he lost control of his carriage when the horses bolted and he died of his injuries four days after the accident. He was succeeded in his title and estates by his elder son Hugh Stewart*.9 Belfast News Letter, 7 June 1825; Gent. Mag. (1825), ii. 466.