The act allowed Catholics to have a seat in parliament. This condition was crucial as Daniel O'Connell had won a seat in a by-election in County Clare but under British law he was forbidden (because of his religion) to take his seat in Westminster. Sir Robert Peel, the Home Secretary, who had for all of his career opposed emancipation (and had, in 1815, challenged O'Connell to a duel) was forced to conclude: "though emancipation was a great danger, civil strife was a greater danger." Fearing a revolution in Ireland, Peel drew up the Catholic Relief Bill and guided it through the House of Commons. To overcome the opposition of both the House of Lords and King George IV, the Duke of Wellington worked to ensure passage in the House of Lords, and threatened to resign as Prime Minister if the King did not give Royal Assent.
The Catholic Relief Act was a compromise, however, and effectively disenfranchised the Catholic peasants of Ireland, the so-called Forty Shilling Freeholders. The act raised fivefold the economic qualifications for voting. Starting in 1793, any man renting or owning land worth at least forty shillings (the equivalent of two Pounds Sterling), had been permitted to vote. Under the Catholic Relief Act, this was raised to ten pounds.