Shaftesbury being a prosperous town this included the vast majority of households, and in 1831 when the borough contained only 474 houses, 400 separate properties were rated for scot and lot and 359 people voted in that year's election.
In the mid 18th century the joint patrons were Lord Ilchester and The Earl of Shaftesbury, who generally agreed to nominate one member each rather than bringing about a contested election which would allow the voters scope to demand bribes.
At that election one candidate, Hans Winthrop Mortimer, stood independently of the established interests in the town and, having been easily defeated, petitioned to have the result overturned and produced copious evidence of corruption.
Thomas Rumbold and Francis Sykes were both shown to have bribed at a rate of 20 guineas (£21) a man, the total spent amounting to several thousand pounds; worse, the magistrates of the town were implicated in distributing this largesse.
A bill was also brought in to permanently deprive the guilty parties of their votes; however this was never passed, the prosecution never took place, and the Commons was eventually persuaded to reverse its condemnations of Sykes and Rumbold so that both were able to stand for the borough at the next general election.
They did not escape penalty entirely, however, as Mortimer brought a civil suit for bribery against Sykes at Dorchester Assizes, and was awarded £11,000 in damages – which he used to buy houses in the town, increasing his own influence at future elections.
His accession seems to have eliminated Shaftesbury's endemic bribery and converted it to a more secure pocket borough: when Edward Harbord was offered the seat in 1820 in token of Grosvenor's admiration for his stand over Peterloo, he described it as "a place where no questions are asked as to political principles, and no money required".