Jonathan Swift, who detested him, called him the son of a cottager who narrowly escaped being hanged for stealing cows.
The plot had been conceived by Sir George Barclay, who landed at Romney in January 1696 intent upon assassinating the King.
Another informer, De La Rue, revealed the plot but the King wanted confirmation from Prendergast, whom he felt he could trust and rely on.
On the morning of the plot, the conspirators heard that guards had been dispatched but soon most of them had been rounded up and were eventually charged, thanks mainly to the testimonies of Prendergast.
Jonathan Swift, a bitter personal enemy of the younger Thomas, extended his hatred to the elder: "him who shamed our isle, traitor, assassin and informer vile".