Hallifax, who was indentured to a Barnsley grocer while still very young, left before his apprenticeship was completed, and went to London where he became a clerk in the banking house of John Martin and Co.
Alderman since 1766, and in 1768 one of the sheriffs, he acted as returning officer for the last three of the four Wilkes Middlesex elections, upholding the rights of free election; and in his capacity as sheriff, in company with the mayor and other members of the corporation, presented a petition to the King against the seating of Luttrell. But when on 6 Mar. 1770 a second petition was presented by some of the aldermen, led by William Beckford, Hallifax, no longer in office, publicly dissociated himself from it. The Ayr bank disaster of 1772 seriously affected Glyn and Hallifax, and in June they suspended payment, but were able to re-open in August. In October 1772 Hallifax stood as court candidate for lord mayor in opposition to Wilkes. He was defeated, and though encouraged by the King and North to demand a scrutiny, seems quickly to have abandoned the idea.
Hallifax was now anxious to find a seat in Parliament, and according to Henry Beaufoy’s account
In 1784 Hallifax was returned unopposed at Aylesbury. He was classed as an Administration supporter by Adam in May 1784, and his one recorded vote on the Regency, 16 Dec. 1788, was in support of Pitt. There is no record of his having spoken in the House, and during his Coventry election campaign he was labelled ‘the Dumb Knight’.
