In 1807 he obtained an interview with the 1st Duke of Wellington, the Chief Secretary for Ireland, who explained that Catholic Emancipation was not at that time practical politics, but that the remaining Penal Laws would be enforced with all possible moderation. As one of the leaders of the Catholic Association in its original form, which the Government maintained was illegal, he was briefly arrested, but never prosecuted. His role led to his being known by the  unofficial title "head of the Irish Catholic laity". In 1815 he  withdrew from any active role in the Emancipation movement, following a series of bitter public clashes with Daniel O'Connell. O'Connell publicly denounced Fingall as "a Catholic nobleman  coldly departed from the cause of his children and  his country". This however was the kind of rhetoric  in which O'Connell frequently engaged in public, and was rarely a guide to his true feelings. In private he admitted to having a great regard for Fingall, whom he described as having a character "as pure as gold". Lord Byron  violently attacked Fingall in verse for accepting the Order of St. Patrick from George IV - wears Fingall thy trappings? - and for his deferential behaviour during the Royal Visit in 1821. However Fingall and his fellow Irish Catholic  peers were not and did not pretend to be republicans: they sought equal rights under the Crown, not separation from it.
In 1807 he obtained an interview with the 1st Duke of Wellington, the Chief Secretary for Ireland, who explained that Catholic Emancipation was not at that time practical politics, but that the remaining Penal Laws would be enforced with all possible moderation. As one of the leaders of the Catholic Association in its original form, which the Government maintained was illegal, he was briefly arrested, but never prosecuted. His role led to his being known by the unofficial title "head of the Irish Catholic laity". In 1815 he withdrew from any active role in the Emancipation movement, following a series of bitter public clashes with Daniel O'Connell. O'Connell publicly denounced Fingall as "a Catholic nobleman coldly departed from the cause of his children and his country". This however was the kind of rhetoric in which O'Connell frequently engaged in public, and was rarely a guide to his true feelings. In private he admitted to having a great regard for Fingall, whom he described as having a character "as pure as gold". Lord Byron violently attacked Fingall in verse for accepting the Order of St. Patrick from Georgia IV-wears Fingall thy trappings?-and for his deferential behaviour during the Royal Visit in 1821. However Fingall and his fellow Irish Catholic peers were not and did not pretend to be republicans: they sought equal rights under the Crown, not separation from it.