Under George I the chief interest at Peterborough was in its Whig custos rotulorum, the 2nd Earl Fitzwilliam [I] of Milton, 3½ miles from the city, which he represented from 1710 till his death in 1728. During this period the other seat was held by Charles Parker, of a Tory town family, till 1722, when he was defeated by Sidney Wortley, formerly Montagu, a wealthy Whig coal owner, M.P. Peterborough 1698-1710. The dean and chapter, a pro-government body, appointed the returning officer.

In 1727 Parker, having been appointed sheriff, which prevented him from standing, used his office to send the precept for the election not to the bailiff of Peterborough, appointed by the dean and chapter, but to the bailiff of Nassaburgh Hundred, whose return of Fitzwilliam and a Tory, Sir Edward O’Brien, he accepted, rejecting that of the bailiff of Peterborough in favour of Fitzwilliam and Wortley. On petitions from the bailiff of Peterborough and the dean and chapter, the House of Commons ordered the indenture returning Fitzwilliam and O’Brien to be taken off the writ and replaced by that returning Fitzwilliam and Wortley, allowing O’Brien to petition on the merits of the election, on which Wortley was declared duly elected, six months after his death in November 1727.1 Soon afterwards Fitzwilliam also died. No one of their families being available, the vacancies were filled by two wealthy Whig strangers, Joseph Banks and Charles Gounter Nicoll, till 1734, when they were succeeded by Wortley’s and Parker’s sons, Fitzwilliam’s heir being a minor. Wortley’s son retained his seat till his death in 1761, but Parker was succeeded in 1741 by the 3rd Earl Fitzwilliam, now of age. Parker recovered his seat on Fitzwilliam’s elevation to the Lords in 1742, but in 1747 he was replaced by the Fitzwilliam family’s agent, Matthew Lamb. Two years later the 2nd Lord Egmont in his electoral survey describes Peterborough as ‘in Wortley Montagu and Lord Fitzwilliam’.