In 1754 on the death of Henry Pelham, Thomas, now the heir of the Pelham family, was advanced to the dignity of knight of the shire. About his financial circumstances he wrote to Newcastle, 6 Mar. 1754:
A good deal of Pelham’s time was spent on Newcastle’s Sussex affairs, in which he acted as the Duke’s chief agent and representative. Quiet and unobtrusive, he accepted patiently Newcastle’s demands, and never complained of the Duke’s querulousness. Newcastle liked him and had his interests at heart, but treated him rather patronisingly. Pelham was no politician and made no mark in the Commons; and his only recorded speech, 29 Nov. 1763, was on a motion for an address of congratulation to Princess Augusta on her marriage.
Before Newcastle resigned in May 1762 he obtained the grant of a barony with special remainder to Pelham. In the months that followed Pelham could do no other than follow Newcastle, and after voting against the peace preliminaries, 10 Dec. 1762, was dismissed from office. Newcastle counted him among the ‘zealous young men’ who were ‘violent’ for Opposition; but Pelham, though he adhered faithfully to Newcastle, was not made for the work of Opposition. Newcastle, however, was grateful for his fidelity, and on the formation of the Rockingham ministry he was given a higher office than the one from which he had been dismissed.
When in July 1766 Chatham replaced Rockingham, Newcastle did not encourage his friends to resign, and Pelham was only too pleased to remain. But in December 1766 Rockingham broke with Chatham and tried to secure as many resignations as he could, especially from those friends of Newcastle who ‘divide their affection and let Lord Chatham in for part’.
That were I a single man [he thus reported the conversation to Newcastle] it would signify but little to me the keeping my place, and that I should readily resign to follow those to whom and to whose principles I should ever profess myself attached, but that as a father of seven children I thought I was not at liberty to put myself out of all power of providing for them. That it was impossible I should be happy whichever part I took, either to resign or remain in office ... His Lordship said he could not pretend to advise, not being certain whether my remaining in was the sure way of providing for my children ... and that he thought it very likely I and many other of our friends who remained in might be turned out. I told him ... that unless I could be assured that his Lordship and the Duke of Portland were convinced that though I remained in office I was in no one article changed from what I had ever been, and that I had not in the least forfeited their good opinion I would not remain a moment, for that I knew my own feelings so well, were I ever to hear myself by chance accused of ingratitude towards them I could never after hold up my head. His Lordship said he should certainly never think that of me.
‘Since I could not drown my seven children’, he added to Newcastle, ‘I was obliged to take care of them’; and so he remained in office—one foot in the court and the other in the Opposition.
Newcastle would not insist on a step contrary to Pelham’s interest, but claimed the right to advise him about the line he should take. About the East India inquiry he wrote to Pelham on 9 Dec.:
On the land tax Pelham could vote against the court with little risk. It was otherwise with the nullum tempus bill, which Newcastle also had at heart. ‘My good and tender friend Tom Pelham ... will be sure to be with you’, he wrote to Rockingham, 13 Feb. 1768. But Rockingham replied, 16 Feb., about his meeting with Pelham:
When he left me he was much distressed and rather doubtful what to do. His difficulty arises from, as he says, having declared that he would not in office vote against Administration ... so far you certainly may rely, that Tom Pelham’s not voting according to your wishes ... cannot proceed from any want of regard to your Grace but from some cause which he perhaps has not strength to get over.
Pelham voted with the court, but Newcastle did not take it amiss. In a letter to Pelham beginning ‘My dearest and best friend’, he wrote, 18 Feb.: ‘I beg you to be easy, and be assured that I am not in the least displeased with you, or uneasy at what you have done. Your goodness to me is such as I can never forget, and I am quite easy and pleased with you in every respect.’
Pelham succeeded to Newcastle’s estates in Sussex but not to the full extent of his political influence—much of that was personal and could not be transmitted to an heir. Rye and Seaford reverted to the Treasury, and the only borough influence Pelham retained was one seat at Lewes. In the Lords Pelham made no mark (‘your little waxen friend’, Walpole had called him in a letter to Mann, 29 Nov. 1756). He supported North to the end, voted for Fox’s East India bill, and opposed Pitt until the French Revolution.
He died 8 Jan. 1805.