From the security of this position, Seymour moved that the Loyal Parliament investigate the irregularities surrounding the election of its members before it granted any revenues to James II, but as no other member dared to second it, it brought about no immediate consequence. He continued to oppose the arbitrary measures of James throughout his reign. During the Glorious Revolution, he was one of the first Tories to declare for the Prince of Orange. The remarks that supposedly passed between the two on the first meeting are indicative of his pride of birth: "I think, Sir Edward," said the Prince, "that you are of the family of the Duke of Somerset." "Pardon me, your highness," replied Seymour, "the Duke of Somerset is of my family." However, he adhered to the Tory party, acting as a sort of whip or manager, and remained a vigorous rhetorical opponent of the Whig. He particularly attacked Lord Somers, the Chancellor, and managed the several attempts made to remove him from office. In 1699, the death of his third son, Popham Seymour-Conway, from the effects of a wound incurred in a duel with Captain George Kirk, prompted him to make an attack upon the standing army. He seems to have suffered from diabetes in later life, an exchange of wit between Seymour and his physician, Dr. Ratcliffe, being recorded in "Joe Miller's Jests". He died at Bradley House, Maiden Bradley. On 7 September 1661, he married Margaret Wale (d. bef. 1674), daughter of Sir William Wale, of North Lappenham, Rutland, Alderman of London, and wife, and sister of Elizabeth Wale, married to the Hon. Henry Noel, of North Luffenham, Rutland, Member of Parliament, by whom he had two children:  In 1674, he married Laetitia Popham (d. 16 March 1714), daughter of Alexander Popham and wife Letitia Carre, by whom he had seven children: