Moore entered the Irish house of commons in 1798 for Sir Edward Denny’s borough of Tralee and opposed the Union. After his return to Westminster, the Castle noted that he had not taken his seat in March 1801 and labelled him uncertain and inactive, adding ‘never will be in again’. He subsequently took his seat and on 1 June opposed George Ponsonby’s Irish courts regulation bill on behalf of the Irish judiciary, while on 10 June he opposed a proposal to exempt John Beresford from disqualification ex officio as ‘odious to the people of Ireland’. That autumn, at Lord Kilwarden’s instigation, Moore became third serjeant, described by the chief secretary as ‘an office without emolument, and long vacant and unsolicited; now filled by a very respectable lawyer and MP’.1Cornwallis Corresp. iii. 67, 164; PRO 30/9/13, pt. 2; Colchester, i. 290.
The Castle solicited and obtained Moore’s attendance in the ensuing session, when he again objected to the reform of the Irish courts, 27 Apr. 1802, but was one of the two anti-Unionists who ‘remained firm’ against John Foster’s anti-Union tirade of 7 May. On 3 June he was teller for the Irish controverted elections bill, which he supported in a speech a week later. On 17 June Ewan Law informed his brother in Ireland:
I am extremely happy to observe so much cordiality between your Members and ours; one of the former Mr Serjeant Moore paid the House a very handsome compliment on that head the other day.2Add. 35713, f. 92; PRO 30/12/17/2/30.
Moore did not seek re-election in 1802, but obtained further promotion in his profession and remained a supporter of administration. In 1811, for instance, he approved the viceroy’s suppression of Catholic meetings. He died 6 Jan. 1846, ‘aged 82’.3HMC Bathurst, 157; Gent. Mag. (1846), i. 669.