His request being refused, he said, "That's hard! not one word!" St.John being out of his reach, he stepped up to Mr.Harley, and exclaiming, "Have at thee, then!" stabbed him in the breast with the penknife which he had concealed.

The instrument broke upon the bone, without penetrating into the cavity; nevertheless he repeated the blow with such force that the chancellor of the exchequer fell to the ground.
Secretary St.John, seeing him fall, cried out, "The villain has killed Mr.Harley!" and drew his sword.

Several other members followed his example, and wounded Guiscard in several places.

Yet he made a desperate defence, until he was overpowered by the messengers and servants, and conveyed from the council-chamber, which he had filled with terror, tumult, and confusion.

His wounds, though dangerous, were not mortal; but he died of a gangrene occasioned by the bruises he had sustained.
This attempt upon the life of Harley, by a person who wanted to establish a traitorous correspondence with France, extinguished the suspicions of those who began to doubt that minister's integrity.