Twelve MPs were returned to the Irish House of Commons from Co. Antrim a potwalloping borough with about 200–350 electors, had been enfranchised by 17 Chas II, and under its charter the Returning Officer was the Seneschal of the Manor of Moylinny, which belonged to the Massereene family. However, in the course of the century many leases on the Massereene estate had been granted in perpetuity, which conferred a degree of independence on the tenants. In the 1776 election for Antrim town the interest of the Skeffington family was seriously but unsuccessfully challenged by a local family, the Thompsons of Greenmount, who had prominent Presbyterian connections. This challenge, which began at a by–election in 1769 and was repeated in 1783 and 1790, was largely due to the character and lack of political interest and support of the then Lord Massereene; contemporary opinion was that 'If Lord Massereene, to whom the town belongs exerted himself, the opposition to the family would be fruitless.' The influence of the perceived owner of a borough was almost invariably an important ingredient in retaining political control, although the one occasion on which Lord Massereene did interfere, in 1769, was nearly disastrous as his agents actually, 'marvellous to tell', appointed Thompson as their agent in Antrim. The countess was informed and intervened; thereafter, Lord Massereene left the maintenance of the family's political influence, and its expense, to his mother and brothers, a fact which was so notorious that at the Union the Commissioners split the compensation for the disfranchisement of the borough between Lord Massereene and his three surviving brothers. In 1774 Massereene's law agent reported that 'There has been a meeting amongst a parcel of hot–headed people who call themselves free and independent, but I imagine [he continued optimistically] that all this frenzy will subside and that the Massereene interest will hold its influence.' In the long term he was correct, but the temper of the times ensured that in the medium term that interest would be tested.
In 1776 there were four candidates for the borough, and the electorate was sharply divided between them. Lord Massereene's two brothers, the Hon. William John Skeffington (1935) and the Hon. Chichester Skeffington (1928), each received 164 votes, while their opponents, Skeffington Thompson and Alexander Stewart, received 134 apiece. On account of 'the illegal measures pursued at this election', Skeffington Thompson and Alexander Stewart petitioned the House of Commons against the return of the two Skeffingtons. Although, as was to be expected, the committee appointed to try the petition decided that Lord Massereene's brothers were duly elected, they concluded with the following resolution:
Resolved: that it appears to this committee that Robert Clarke, Seneschal of the Manor of Moylinny, who presided as Returning Officer at the late Election of Burgesses to serve in Parliament for the borough of Antrim, has acted illegally, by refusing to administer the Oath of inhabitancy prescribed by Law, to several Persons who demanded the same, in order to entitle them to vote at the said Election; and also by suffering several Witnesses to be sworn and examined, touching the Qualifications of such Persons, and refusing to permit them to vote at the said Election in consequence of such Examination.
The only borough official was the Seneschal of the Manor of Moylinny. Lord Massereene paid the chief rent for his Co. Antrim estate, which included the manor, to Lord Donegall but as the de facto owner the Massereenes' appointment of the Seneschal, with his wider political duties, was unquestioned. Travelling to Dublin to attend election committees of the House of Commons was extremely unpopular and frequently, as in this case, great efforts were made by witnesses to avoid being summoned:
And Sir Capel Molyneux (1421) likewise informed the House that he was directed by the Committee to acquaint them, that Joseph Redford, Esq., of Antrim, absented himself, and closed his Doors and Windows, in order to prevent his being served with a summons for his Attendance on the said Committee.28
Previously the borough had been under the care of Lord Antrim, as Lord Massereene had 'run himself into great difficulties by gaming'. Under these circumstances it appears probable that this conflict was largely due to neglect on the part of the patron. Thompson, about whom little is known, may also have had an interest in the linen manufacture. In 1803 Lord Massereene described Thompson's grandson as 'a farmer and a cloth merchant, living at Greenmount', and there is a possibility that the burgeoning linen industry brought a new element into Antrim which might not have had the same attachment to the Skeffingtons. Also, Antrim and Templepatrick are close and are not far from Belfast, thus it is possible that Antrim was affected by the recent unrest in the vicinity. It is also possible that Thompson received some encouragement from John O'Neill, who had unsuccessfully challenged the Skeffingtons, and contested the result, in the county election of 1761. In the other county Antrim boroughs, Randalstown, Lisburn and Belfast, the patron's influence was uncontested in 1776 and their nominees were automatically returned.
Considered as a whole, the 1783 election was a quiet one in Co. Antrim, for, with the sole exception of Lisburn, the influence of the Volunteers prevailed without a contest. In Antrim the Thompsons made another attempt but were so decisively defeated that when the outcome became clear Skeffington Thompson declined to complete the poll, although it is possible that at one stage he tried to come to an agreement to divide the representation, thereby provoking the wrath of the formidable Dowager Countess.
At the 1790 election for Antrim, Thompson mounted a final challenge to the Skeffingtons, harrassing them with various legal actions as well as mounting a challenge against their return, which resulted in William John Skeffington being declared elected but Chichester Skeffington being not duly elected, as were Thompson and his ally Nicholson. However, they were not debarred from seeking to be re–elected and in a straight fight with Thompson, Chichester Skeffington won by 137 to 121 votes by his own reckoning or, according to the Belfast News Letter, a more modest 70 to 69, suggesting a bitter fight and a large number of votes disqualified on both sides. This marked the end of the Thompsons' challenge. Exactly why the Thompsons made such a tenacious and expensive stand is far from clear. Were they socially ambitious? Was it for business reasons, if they were in business at this time? Was it for personal reasons? Did they enjoy the expensive challenge of litigation? Unfortunately, little is known of their side of this saga.
Indisputably such a challenge was expensive to both parties and Thompson may have hoped that, given the straitened finances of the Skeffingtons and the erratic behaviour and curious circumstances of the Earl of Massereene, he could force their acquiescence in granting him at least a share in the borough. The Thompsons' challenge was expensive; the by–election in 1769 had cost the Countess £66, but the disputed election case in 1776 cost the family £700, and as Thompson had charged bribery and undue influence, there were probably considerable other charges in connection with the actual election. Certainly by 1791, when Skeffington Thompson made his final attack, the Skeffingtons had cause to be worried financially. But they were trapped, as their parliamentary seats ensured the jobs that were their livelihood. In 1809 it was stated in a law court that Chichester Skeffington had made a fortune of £50,000 to £100,000 out of the borough, and in addition it had made provision for his brothers. A parliamentary borough was part, and often a substantial part, of a family's assets as well as increasing their social consequence. Had Antrim been a 'close' corporation they might have lost control, but it was a potwalloping borough and, as lords of the soil and designators of the returning officer, they were in a position to fight off even as determined an attack as that made by the Thompsons. Antrim was disfranchised at the Union, and the £15,000 divided among the four surviving Skeffington brothers.