As an MP he published a letter on the reasonableness of the Stamp Act, 1765, which earned him a place in the events that led to the American Revolution.
From 5 April 1764 until its dismissal in July 1765 he held the post of secretary to the treasury in George Grenville's administration, before going into opposition.
[1] On Grenville's death in November 1770, Whately attached himself to Lord North, and acted as the go-between for his old patron's friends.
Junius denounced him as possessing "the talents of an attorney" and "the agility of Colonel Bodens" (who could scarcely move), and for deserting Grenville's cause.
[1] Whately was the author of Remarks on "The Budget," or a Candid Examination of the Facts and Arguments in that Pamphlet (1765), rebutting David Hartley's attack on Grenville's financial schemes, and he also defended his chief in Considerations on the Trade and Finances of the Kingdom and on the Measures of the Administration since the Conclusion of the Peace (3rd edit.
[1] Whately has sometimes been credited with the authorship of a pamphlet on the Present State of the Nation (1768; appendix, 1769), but it was drawn up, under Grenville's supervision, by William Knox.
I always walked over the gardens with his book in my hand, examined with attention the particular spots he described, found them so justly characterised by him as to be easily recognised, and saw with wonder, that his fine imagination had never been able to seduce him from the truth.
After Whately's death, correspondence directed to him from Thomas Hutchinson, governor of Massachusetts, Lieutenant-Governor Andrew Oliver, and other British colonial agents was leaked to Benjamin Franklin.