the end of 1782, when he represented the borough of Newtown in the Isle of Wight. He made his first speech in the House of Commons on 20 Feb. 1775, in the debate on Lord North's propositions for conciliating the American colonists. Dundas showed his independence by alluding ‘in very strong terms’ to the inconsistency of the prime minister, and declared that he could never accede to any concessions whatever ‘until the Americans did, in direct terms, acknowledge the supremacy of this country; much less could he consent to such concessions while they were in arms against it’ (Parl. Hist. xviii. 332). He spoke again on 6 March in favour of the bill for restricting the trade of the New England colonies, and in reply to Thomas Townshend, who had urged the injustice of an act which made no discrimination between the innocent and the guilty, but starved all alike, declared that the bill, which was both just and merciful, ‘had his most hearty approbation,’ and that, ‘as to the famine which was so pathetically lamented, he was afraid it would not be produced by this act’ (ib. 387–8). On 24 May 1775 he was appointed lord advocate in the place of James Montgomery, who had been made chief baron of the exchequer in Scotland, but it was not until 20 July that Dundas presented his commission in the high court of justiciary. From this time Dundas devoted his attention chiefly to politics, though at first he regularly appeared as the public prosecutor in the Scotch courts. In 1777 he was appointed joint keeper of the signet in Scotland, but still continued to oppose every plan for effecting a reconciliation with the American colonists.
In February 1778 his support of Powys's amendment for the repeal of the Massachusetts charter made the king so indignant that, in a letter to Lord North, he declared ‘the more I think on the conduct of the advocate of Scotland, the more I am incensed against him; more favours have been heaped on the shoulders of that man than ever were bestowed on any Scotch lawyer, and he seems studiously to embrace every opportunity to create difficulties; but men of talents when not accompanied with integrity are pests instead of blessings to society, and true wisdom ought to crush them rather than to assist them’ (Letter 454). The king, however, recognising Dundas's use as a debater, soon afterwards became reconciled to him, and on 21 April 1779 wrote to Lord North: ‘Let the lord advocate be gained to attend the whole session and let him have the confidence concerning measures in parliament’ (Letter 561). On 14 May 1778 Dundas gave notice of his intention to bring in a bill, similar to Sir George Savile's, for the relief of the Roman catholics in Scotland (Parl. Hist. xix. 1142). But the agitation which was immediately commenced in that country against the proposed toleration assumed such formidable proportions that Dundas was obliged to abandon his intention. To such an extent had sectarian bitterness been aroused, that, though in the general assembly a motion against the proposed change had been defeated by a large majority in May 1778, in the following year a resolution was passed by the same body declaring that ‘a repeal of the laws now in force against papists would be highly inexpedient, dangerous, and prejudicial to the best interests of religion and civil society in this part of the United Kingdom.’
Dundas took a prominent part in the debate on Dunning's famous resolution relating to the influence of the crown on 6 April 1780, and tried to end the discussion by moving that the chairman should leave the chair, but ultimately withdrew this motion and moved the addition to the resolution of the words ‘that it is necessary to declare.’ This amendment, which was made apparently for the sake of gaining time, was immediately accepted by Fox, and Dundas thereupon voted with the government in the minority (ib. xxi. 360–1, 366, 374).
In April 1781 he was made chairman of the secret committee appointed to report on the causes of the war in the Carnatic and the state of the British possessions in that part of India. On 9 April 1782 he moved that the six reports which he had presented should be referred to a committee of the whole house, and in a speech lasting nearly three hours strongly condemned the mismanagement of the Indian presidencies (ib. xxii. 1275–83). On 30 May following his resolutions declaring that Warren Hastings and William Hornby (president of the council of Bombay) having ‘in sundry instances acted in a manner repugnant to the honour and policy of England,’ ought to be removed from their respective offices, were agreed to (ib. xxiii. 75–6). But though an order for the recall of Hastings was made by the directors, it was subsequently rescinded, and he remained in India until 1785. Dundas retained the office of lord advocate during the Rockingham and Shelburne administrations, and on 19 Aug. 1782 was also appointed by the latter minister treasurer of the navy. He was admitted to the privy council on 31 July 1782, and was also given the office of keeper of the Scotch signet, as well as the patronage of all places in Scotland (Fox, Memorials and Correspondence, 1853, ii. 29). Shortly before Shelburne's downfall
