 To bolster his position he resolved to enter the British House of Commons.He was returned unopposed as Member of Parliament for Midhurst by the patronage of Charles Seymour, 6th Duke of Somerset at a by-election on 27 February 1717.He supported Charles Spencer, 3rd Earl of Sunderland until they fell out 1719 over the Peerage Bill, which Sunderland had promoted but which Midleton opposed, and he was ignored until Sunderland's death in 1722.