The constitutional crisis Bradlaugh created ran for six years and was resolved, characteristically, by his own stubbornness. Elected member of parliament for Northampton in 1880, he asked to affirm rather than swear the religious oath; the House refused, and when he then offered to take the oath as a matter of form, it refused that too, on the argument that an atheist's oath could not bind. What followed became a parliamentary war of attrition. Bradlaugh was excluded and unseated, and Northampton returned him again at by-election after by-election, in 1881, 1882 and 1884, and again at the general election of 1885. He was briefly held in the Clock Tower of the palace itself in 1880, once strode to the table and administered the oath to himself, and fought and lost test cases whose costs nearly broke him. Public meetings across the country took up the cause, which had become, as he insisted, not about atheism but about the right of electors to choose their member.
In 1886 a new Speaker, Arthur Peel, declined to intervene, and Bradlaugh simply took the oath and his seat. He spent his remaining years as an effective and respected radical member, and his Oaths Act of 1888 secured for members and witnesses alike the right of affirmation he had been denied. In 1891, as he lay dying, the House of Commons expunged from its records the resolution that had excluded him, an apology Parliament pays to almost no one.