In 1754 Ashburton was controlled by John Harris of Hayne, through his marriage to the heiress of the Tuckfields, who had owned a moiety of the manor. When his wife died, a month before the general election, the property passed to his step-daughter, Lady Orford. To James Buller she wrote, 5 Apr. 1754:1

I imagine that Mr. Harris of Hayne has applied to you in relation to Ashburton; the estates of my late uncle Mr. Roger Tuckfield having descended to me on my mother’s death has very much alarmed him, and with so much the more reason, as his behaviour to me on that event has been unprecedented, but unfortunately the general election is too near for me to be able to act at present, with any certainty of success.

Harris was returned unopposed, bringing in a follower of Newcastle with him.

At the next general election there was strong competition for the seats. Harris stood again, and Lady Orford gave her interest to her cousin by marriage, Thomas Walpole. The Duke of Newcastle succeeded in moving on Sir Thomas Clarke, the lawyer, and Nathaniel Newnham, a London merchant, who claimed that ‘the great services I have already done and may do that borough in promoting the exploration of its manufactures has procured me several staunch friends there’.2 But there was still a scramble. Laurence Sulivan, one of the candidates, was a close friend of both John Dunning and Robert Palk, natives of the borough, and was under the protection of Lord Shelburne: John Duke, the fourth candidate, owned the other moiety of the manor. The Administration candidates had a comfortable majority at the poll, but Sulivan petitioned, complaining that Harris had granted collusive conveyances to many of his servants and dependants.3 The petition was eventually dropped.

Before the next vacancy, in 1767, Lady Orford had made over her interest in the borough to her son, the 3rd Earl of Orford: Robert Palk and his friends had also succeeded in building up a powerful interest. In the summer of 1767 Shelburne made overtures to Orford, through Dunning, asking him to bring in Sulivan. On 4 Oct. 1767 Orford wrote that, in the event of Harris’s death, which was imminent, he would be ‘open to an accommodation’.4 His first claim was for both the seats at the general election: in return he was prepared to bring in Dunning for Castle Rising. ‘My aim’, explained Dunning to Shelburne, ‘has been to bring about an agreement for one and one at the next general election.’5 Orford soon climbed down, and wrote to Shelburne:

I agree to concur in choosing Mr. Palk on the present vacancy—in order to settle matters on a peaceable and lasting foundation—but I expect an ample declaration from Mr. Palk that he only means and wishes to represent the town for this session, and that he and his friends will support Mr. Boone and Mr. Sulivan at the general election.

This compromise lasted the rest of the period, Orford bringing in Boone and Robert Mackreth, and Palk taking over the other seat from Sulivan in 1774.6 An opposition in 1784 by Sir Ralph Payne, a Coalitionist, who put up Lord North as candidate, was nugatory.