Returned at Ashburton on the interest of John Harris, Midleton throughout his parliamentary career was a close follower of Newcastle. In 1756 Newcastle offered him a place at the Board of Trade which Midleton refused, fearing he might not be returned again at Ashburton, where in any case he was not ‘very ambitious ... of the honour of a second recommendation from Mr. Harris’.
I do not imagine that your Grace would have given the same answers as you have given to me, to a person whom you really intended to serve, and therefore I look upon them to be meant to prevent any future application from me ... These things which I have mentioned I have the vanity to think I had a right to ask for. And I think also that if my connexions had been with other persons I should not so frequently have failed in my applications.
Nevertheless: ‘As a minister, and the head of that set of men ... whom I shall ever consider as the truest friends to this country my respect for your Grace can never fail.’ He received no appointment, but at the general election Newcastle introduced him at New Shoreham where he was returned unopposed, and at Newcastle’s request on 13 Nov. 1761 he moved the Address.
Midleton remained with Newcastle when he went into opposition, and strongly opposed the peace terms, introducing the motion to postpone consideration of the peace preliminaries, 1 Dec. 1762. In January, 1763 Newcastle wrote that Midleton, with Lord Villiers and Thomas Pelham, was determined ‘to cry aloud and spare not’ in opposition.
