Rushout’s grandfather was a Flemish merchant, naturalized in 1634. His father bought an estate near Evesham, which he represented for nearly twenty years. In an account of his own career he writes:
When I first came into the army I was a younger brother, I served six or seven years in the Blue Regiment of Horse Guards and was promoted to the command of a troop in the year 1710 which I quitted with great regret two years afterwards when the Duke of Ormonde had the command and was garbling the army with a view to defeat the Hanoverian Succession, and I had reason to expect I should not have been allowed to have continued in it. About the same time my family estate fell to me, and I was elected into Parliament.
Add. 32862, f. 218.
He sat for Malmesbury till 1722, when he was unseated there on petition but was also returned for Evesham, which he and his son thenceforth represented without a break till 1796.
In the first Hanoverian Parliament Rushout voted against the septennial bill, for the repeal of the Occasional Conformity and Schism Acts, and was absent on the peerage bill. In the next Parliament he initiated the House of Commons inquiry into the Atterbury plot, and in 1725 sponsored the complaint leading to Lord Macclesfield’s impeachment, of which he was a manager. Following his friend, Pulteney, into opposition, he spoke against a vote of credit, 25 Mar. 1726, and introduced a bill against election bribery, 27 Apr., which passed the Commons but was lost in the Lords. In 1727 he rose at the end of a finance debate,
and after having said some reflecting things in an awkward manner as if the Treasury were answerable for mismanagement in every office concluded with a motion and a personal question on Sir Robert Walpole
Knatchbull Diary, 15 Jan. 1723 and 23 Jan. 1725, 7 Mar. 1727. .
His defection was attributed to an unsuccessful application which he had made for the post of treasurer of the Household.
For the rest of Walpole’s Administration Rushout remained in opposition, closely associated with his nephew, Samuel Sandys, and Phillips Gybbon as Pulteney’s chief supporters. He acted as Pulteney’s second in his duel with Lord Hervey in 1731, when he also chaired a select committee of the House of Commons, whose report led to the passing of the Molasses Act. During the excise bill crisis in 1733 he was put down as secretary at war in the list of a new ministry prepared by the opposition leaders.
a bill for further regulating elections was presented by Sir John Rushout to the House. This bill went as far as a committee and there dropped, there being so many various opinions of gentlemen for the sake of their particular interests in their boroughs.
He spoke in favour of an increased allowance to the Prince of Wales on 22 Feb. 1737.
On Walpole’s fall Rushout, Sandys, and Gybbon became Pulteney’s representatives on the new Treasury board, where they combined to outvote the first lord, Wilmington.
Sir John Rushout ... actually forgot he was lord of the Treasury. He got up to speak and when he came to the point of Hessian and Hanoverian troops was against ’em, and went so far as to say he saw as little occasion for them this year as there was the last. Mr. Pelham and Winnington stared him in the face, which put him in mind who he was, so he said the heat of the House overcame him, and so sat down.
Hen. Finch to Ld. Malton, 18 Nov. 1724, Wentworth Woodhouse mss.
On the day of Wilmington’s death, 2 July 1743, a servant of Rushout’s was sent to the King in Hanover with a letter from Pulteney, now Lord Bath, applying for the vacancy. When Pelham was appointed to it, Rushout and Bath’s other adherents on the Treasury board were ‘awkward and cold’, seeming to be only waiting for an opportunity to treat Pelham as they had treated Wilmington.
When Bath and Granville made their abortive attempt to form an Administration in February 1746, they found that ‘in the Commons ... they had no better man to take the lead than poor Sir John Rushout’.