Earl Fitzwilliam, the principal property owner, was unopposed parliamentary patron of this open borough throughout the period. He described Peterborough in 1796 as ‘a place where we have no trouble, but where we always pay great attention’. French Laurence, after his return, informed his patron, 16 Nov. 1796, that he had endeavoured ‘to give the proceeding the air of a free and independent election without the mention of freedom, and independence, and at the same time to keep your lordship ever before their eyes’.1 Fitzwilliam’s choice of Members was a ‘mixture’ of ‘distinguished persons, suitable persons, family connexions, ancient friendships’, so he claimed.2 In 1806 both Laurence and Elliot were prepared to make way for Lord Milton, Fitzwilliam’s heir, who was of age, ‘in that seat which most naturally belongs to him’; but when he gained the county seat, they remained in possession.3 When William Windham* was without a seat in 1807, both Members felt disposed to make way for him, but appreciated that there were decencies to be observed towards the electors which made the substitution difficult to arrange. An arrangement did come off in 1809 when, on the death of Laurence, the patron recommended the Marquess of Tavistock, who would otherwise, on his coming of age, have displaced his locum tenens George Ponsonby at Tavistock.4 In 1812 they exchanged seats.

In 1816, when Ponsonby found a county seat, William Lamb, on whose behalf Lady Bessborough had applied in 1812, replaced him. His patron expected him to oppose parliamentary reform and he was informed that the expense would be £600 to £700: ‘it will be besides necessary, once in a year, to come down to pay court to the principal persons by a call at their doors, to dine at a club, but no expense attending it’.5 On Elliot’s death late in 1818 there was much speculation as to his replacement and the choice of Scarlett caused some surprise, as he had ‘no connection’ with his patron. George and William Ponsonby and Charles Cavendish were mentioned in Whig circles for the vacancy; Lord Milton thought of Sir Robert Heron and George Strickland of Boynton; while Sir Francis Lindley Wood, ‘a private Yorkshire friend’ was also considered.6

A second vacancy in 1819 was filled by Sir Robert Heron, who met with some hostility. A letter of 17 Nov. to the patron, signed by 26 respectable inhabitants, made a ‘plain but respectful avowal’ of dislike of Fitzwilliam’s choice. Lord Milton, in a letter to Dr Strong, one of the signatories, 20 Nov., remonstrated: Peterborough nominees had been men ‘more than usually eminent and conspicuous above their fellows ... Heron at least is undoubtedly one of the most considerable Members of the last Parliament who have not been elected to the present.’ He went on to deny the aspersions cast on Heron’s ‘moral and religious character’, regarding them as insulting to his family. Three days later, Fitzwilliam reported:

It now comes out that Sir Robert is objected to because he votes thick and thin in opposition—is therefore an improper representative of the ever loyal city of P[eterborough]—no longer then the holy city—politics override religion.

Heron, who admitted that ‘the high church’, led by Bishop Marsh, was ‘terribly hostile, both to the family at Milton, and to myself’, reported that Milton, who championed him on his canvass, ‘spoke with great emotion, and even shed tears; he defended me most honourably, and with far more effect than I could have defended myself’. He emerged, in his own estimation, ‘the most acceptable candidate they have long or ever had’.7