In 1761 Charles Jenkinson classed Lewes with Aldborough and Boroughbridge as boroughs where the Duke of Newcastle returned both Members.1 Newcastle owned a good deal of property in the town; and his seats at Halland and Bishopstone and Thomas Pelham’s seat at Stanmer, all within ten miles of Lewes, provided custom for local tradesmen. But Lewes was by no means a pocket borough: it had voluntarily placed itself under Pelham patronage, and had to be treated accordingly. It liked to be represented by Pelhams or local men, and did not willingly accept Newcastle’s friends or dependants who had no local connexions. After 1754, when Newcastle could no longer find suitable candidates from his own family and began to bring in strangers, it became increasingly difficult to manage.

At the dissolution of 1754 the Members were Thomas Sergison and Sir Francis Poole. Both were Sussex men: Sergison, who owned property in the town, had contested the borough on his own interest in 1734, 1741, and 1743, but in 1747 had stood as Newcastle’s candidate; while Poole was married to a Pelham. In 1754 both were returned unopposed. In 1761 an opposition was threatened from John Fuller and George Medley, but they did not go to the poll.

Both Poole and Sergison died before the general election of 1768, and Newcastle had considerable difficulty in choosing their successors. On 31 Jan. 1763, when Poole’s death was expected, he explained his dilemma to Hardwicke:2

In my present situation a populous election is disagreeable, though I have not the least doubt of success if we can get a proper man. I have no relation of my own who can stand. The gentlemen of the town, though all good men and proper enough, yet they are so much upon an equality that there may be a difficulty in giving a preference to any of them.

After a considerable search he selected William Plumer, a stranger both to himself and to Lewes, but who was recommended by the Duke of Devonshire. Henry Fox was ready to back a candidate against Newcastle, and seems to have offered Government support to both Fuller and Medley; but nothing came of it and Plumer was returned unopposed. On Sergison’s death in 1766 there was less trouble: Newcastle soon found a candidate, and the nearness of the general election and Grafton’s unwillingness to interfere discouraged opposition.

Newcastle began to prepare in good time for the general election of 1768, and adopted as his candidates Plumer and Thomas Hampden, of an old Sussex family. In January 1768 he had a serious illness from which he never fully recovered, and henceforth his behaviour was even more incoherent than usual. Much of what happened at Lewes may be traced to this.3

When in February 1768 Plumer withdrew to stand for Hertfordshire Newcastle became ‘very uneasy about the town of Lewes, not having ... a proper person to recommend’. The town wanted a local man and Thomas Hay was suggested as one who would be acceptable, but Newcastle was determined ‘to bring no man in ... who shall not ... in all parliamentary questions ... follow and do whatever the Duke of Newcastle shall advise’.4 He believed that Hay, an army officer, would go with the court. But unable to find an alternative candidate and learning that there was ‘a strong inclination to have Colonel Hay at Lewes’, on 11 Feb. Newcastle adopted him; and on 19 Feb. Hay gave assurances as to his conduct in Parliament.

Still Newcastle had grave doubts. On 16 Feb. he had written to William Michell, his agent at Lewes:5

There is another strong objection to Colonel Hay which it is impossible for me, who am at the head of my family and name, to get over. I have for the service of the town and agreeable to what was the practice of my ancestors fixed the family of Glynde to have one [Hampden], and if Glyndebourne is to have the other [Hay] it is a total exclusion of every one of the name of Pelham.

His attitude to Hay cooled when a suitable alternative candidate was found in Thomas Miller, and changed completely when he realized that Hay was persona non grata to the Pelhams of Catsfield, a junior branch of the family. On 24 Feb. Thomas Pelham wrote to Newcastle:

Your Grace knows the consequence Jack Pelham is of in the town of Lewes. ... You likewise know how very ill Colonel Hay and his family have used both Jack Pelham and his brother; I fear therefore I shall have the greatest difficulty to satisfy him, as he has not been apprised in the least of your Grace’s intentions towards Hay. I wish therefore your Grace would insist on Hay’s writing to Jack and Harry Pelham ... to ask their interest for Lewes.

The plan for a reconciliation between Hay and the Catsfield Pelhams failed; and Newcastle now decided to replace Hay by Miller, giving as his reason that Hay’s election would be ‘a perpetual exclusion of all of the name of Pelham’.

But Hay had already canvassed the town as Newcastle’s candidate; and many of the Pelham party, having promised him their votes, would not go back on their word. Newcastle did all he could for Miller but was too ill to go to Lewes himself, and Miller had started too late to have much chance of victory. Newcastle was deeply hurt at ‘the base and ungrateful behaviour of the town of Lewes’;6 and decided to punish them: he would give no plate for the races, provide no entertainments, ordered his tenants who had voted against him to be evicted, and withdrew his custom from the tradesmen who had similarly offended. This was displeasing to Thomas Pelham, Newcastle’s heir, who feared it would strengthen the enemies of the Pelham party; as did also the Duke of Richmond, who wrote to Newcastle on 10 June:7

It will be a handle for them to say that your friendship for Lewes was only for the sake of choosing the Members, that you looked upon them as slaves who were not only to obey your orders but to guess your will, that the moment they presumed to think of choosing one gentleman of the town to represent them they were directly to meet with your Grace’s displeasure.

Advised by all his friends not to adopt such extreme measures, Newcastle was content to accept apologies from his tenants and tradesmen; and that of one of them is typical of the dilemma in which many had been placed:8

William Lee—Printer—Says he is sorry to have offended his Grace, but really thought he was doing what his Grace would have approved.

Thomas Pelham succeeded to Newcastle’s property in Sussex but, without Newcastle’s prestige, he could only hold one seat at Lewes. In 1774 there were six candidates, four of whom stood the poll; and Hay and Miller, the Pelham candidate, were elected. The combination of a Pelham and a townsman was successful in 1780 and 1784.