A leading member of the October Club, Annesley stood at the 1715 election for the fourth time on Lord Abingdon’s interest at Westbury. After a double return he was seated on the merits of the return only to be unseated two months later on the merits of the election. In October 1716 he was appointed one of the trustees of Lord Bolingbroke’s forfeited personal estate.
Outside the House of Commons he was a successful lawyer. The 1st Earl of Egmont describes him as ‘a man of strict honour and secrecy ... I have made use of him from a child ... he did all Lord Shelburne’s business’. He continued in charge of Egmont’s affairs until December 1743, when, at the age of 80, he was attacked by palsy. His son Arthur took out a writ of lunacy against him in 1746.
