In 1763, and again in 1768, Warkworth was returned unopposed for Westminster. In Parliament he, like his father, supported Grenville’s Administration, and on 26 Feb. 1764 Grenville himself referred to Warkworth’s ‘constant and kind attendance’ during the debates on general warrants.1To Northumberland, 26 Feb. 1764, Grenville letter bk. On 10 Jan. 1765, moving the Address, Warkworth referred to the peace as ‘the most honourable, glorious, and advantageous, that ever was made’.2Harris’s ‘Debates’. He voted against the repeal of the Stamp Act, 22 Feb. 1766. Percy, as he was known after his father obtained the dukedom in October 1766, supported the Chatham Administration, and in 1770 seems to have gone over to Opposition with his father; he voted against the Administration on the Middlesex election, 25 Jan. 1770; was classed as an opponent in both Robinson’s lists on the royal marriage bill, March 1772; again voted with Opposition on the naval captains’ petition, 9 Feb. 1773; but with Administration on the Middlesex election, 26 Apr. 1773. He once more voted with Opposition on Grenville’s Election Act, 25 Feb. 1774.
In April 1774 Percy’s regiment was ordered to America, and though his parents strongly opposed his going there, and his mother applied to the King to have him exempted, Percy insisted that ‘it was his indispensable duty to accompany his regiment’.3Ld. Suffolk to the King, Fortescue, iii. 63-64. He sailed in May and arrived at the beginning of July. On 27 July he wrote to his father from Boston:4C. K. Bolton, Percy Letters, 28.
A change of Administration or measures would be, at this instant, the most fatal thing in the world to this province, and all America in general, for it would be adding fresh fuel to that flame which the frequent changes in both were the origin of.
Nevertheless, Robinson’s survey of September 1774 classed Percy as an opponent, and during the election contest in which Percy was re-elected at the head of the poll, a pamphlet addressed to the electors of Westminster, defending his absence on active service in America, stated: ‘It is well known his Lordship disapproved of those very measures which rendered the present service necessary.’5Add. 33123, f. 3. Horace Walpole commented:6Last Jnls. i. 399. ‘Westminster was in equal danger of being lost to the court, Lord Percy ... was only more welcome to them than a nominee of Wilkes, but he was in America, a penurious and undignified young man, and his father connected with Lord Chatham.’ Yet on 25 Jan. 1775 Percy in a letter to his father gave a different impression of his attitude: ‘Both parties here are waiting impatiently for the determinations on your side of the Atlantic’, he wrote. ‘If Great Britain relaxes in the least, adieu to the colonies. They will be lost forever.’ And on 9 Feb. to General Harvey, repeating that orders were anxiously awaited:7Percy Letters, 47, 48. ‘I hope they will be pointed and effectual ones; for you left so many loopholes in the last Acts you passed, that it was found not possible to enforce them.’ Percy remained in America for two more years, distinguishing himself at the retreat from Lexington, and in the campaign round New York, but his relations with Howe became increasingly bad, and early in 1777, having received news of his mother’s death and his own accession to her peerage, he obtained leave to return to England.
He died 10 July 1817.