On 15 April 1754, North, then twenty-two, was elected unopposed as the Member of Parliament for the constituency of Banbury. He served as an MP from 1754 to 1790 and joined the government as a junior Lord of the Treasury on 2 June 1759 during the Pitt–Newcastle ministry (an alliance between the Duke of Newcastle and William Pitt the Elder). He soon developed a reputation as a good administrator and parliamentarian and was generally liked by his colleagues. Although he initially considered himself a Whig, he did not closely align with any of the Whig factions in Parliament, and it became obvious to many contemporaries that his sympathies were largely Tory.