Kinnaird’s ‘native assurance’ was reinforced by an elaborate education. At Edinburgh he was president of the Speculative Society. Before he went to Switzerland in 1800 Lady Holland reported: ‘He is clever and willing to please; one cannot pity him for shyness, as he labours under no embarrassment upon that score ... He is an eager politician against ministers.’ This was the less surprising as his father, partner through his wife in a London bank, had been treasurer of the Friends of the People and remained a political frondeur. Soon after his return from abroad and presentation at court in May 1802 Lord Kinnaird, who seems at first to have had Hedon in mind for him, sent him to Leominster, without any connexion there, to contest the borough.
Kinnaird was ‘impatient to open’ in debate. Fox, whose adherent he was, regretted that he did not encourage him to attack ‘the low estimates’, but ‘was delicate against advising him to débuter upon what was supposed to be unpopular ground’. As it was, Kinnaird tackled the commission of naval inquiry, 15 Dec. 1802, and secured a motion for the production of the patents of the Admiralty and Navy boards to ascertain whether they did not have powers to put their own house in order without reference to parliamentary jurisdiction. On the strength of this, he went on to oppose the third reading of the naval inquiry bill, giving four reasons, most significant among which was the increase of crown influence in the appointment of commissioners. He welcomed the amendments to the bill which weakened the commissioners’ powers, but complained, 27 Dec., that it had been ‘changed at nurse’ to meet the requirements of St. Vincent at the Admiralty. On 1 Mar. 1803 he took leave of absence, but on 4 Mar. favoured inquiry into the Prince of Wales’s financial claims, as the provision made for the Prince was inadequate. It was on this occasion that in gesticulating he knocked a Member’s hat off, ironically Hurst’s, a nominee of the Duke of Norfolk whose interest he had defeated at Leominster. On 21 Mar. he expressed an interest in Indian affairs, and on 28 Mar. secured the same treatment for Scotland as for England in the militia officers bill. He warned the House against hidden interests behind the Edinburgh road bill, 25 Apr. All these ‘little speeches’, his friend Henry Brougham cautioned him in a ‘caustic philippic’, would have been better supplied by ‘a little book’: only to be cut by Kinnaird for his pains. On 15 Mar. he had joined Brooks’s Club. He laughed loudest at Addington, 19 May, and voted with opposition on the resumption of hostilities, 24 May. He assailed the property tax in vain on the grounds that it could not be applied to Scotland under the articles of the Union, 18 June, 5, 13-16 July. While he welcomed the defence bill, 20 July, he complained that it came too late, without consultation with Fox, and repressed ‘the voluntary spirit of the nation’. He himself was a volunteer officer and in December 1803 joined his corps: Brougham commented, ‘he is of more use there [in Scotland] than in Parliament, and cannot easily expose himself so much’ and added that Kinnaird’s fault was want of ‘character’—he had ‘a certain quickness and flow of animal spirits’ but was distrait and over compensated for it by a gushing condescension which only led to his being thought ‘mighty or distant’.
Kinnaird was reluctant to engage in military affairs, but there was nothing for it.
Kinnaird’s chief preoccupation that session was his own campaign for the investigation of naval administrative abuses. On 5 Feb. 1805 he moved for information on the repair of ships under his command by Sir Home Riggs Popham, which led to complaints against the navy board and against Sir Andrew Snape Hamond in particular, 25 Apr. Kinnaird turned on Hamond, 7 May, but next day Pitt insisted on a ballot for the select committee of inquiry moved for by Kinnaird and carried his point. In revenge Kinnaird supported the attack of John Jeffery on St. Vincent’s naval administration, 1, 11 July, but was unable to prevent a navy board cover up, 12 July. Before he could resume his activities, to his dismay he succeeded his father in the peerage. In 1806, when he sponsored the return of Francis Horner to Parliament, he asked his friends in office to make him a British peer, but had to be satisfied with a brief interlude as a Scots representative peer. Thereafter he was reduced to ‘whispering, gesticulating and prophecizing’.
Inevitably, with his penchant for radicalism, he got into scrapes. He was exiled from Paris after the restoration ‘for saying the Bourbons were old women’ and expelled from Belgium and arrested in Paris in 1817 after revealing a plot to assassinate the Duke of Wellington, but refusing to disclose his source. Wellington intervened to prevent his imprisonment. His ‘ill health forbade exertion’. Not long before his death he was ‘just as lively, clever, eager, agreeable and passionate’ as ever, but, reflected a friend, ‘such talents and activity’ were rendered useless by his ‘disqualification’ and ‘give him more pain than pleasure’.