Chief Secretary for Ireland, and was sworn a member of both the British and Irish Privy Councils. He resigned the chief secretaryship after the general election in April 1857, and thenceforth assumed a more independent position in the House of Commons. With Robert Lowe, afterwards Viscount Sherbrooke, he resisted the Reform Bill brought in by William Ewart Gladstone in March 1866. John Bright, speaking on the second reading (13 March 1866), ascribed Mr. Lowe's hostility to Horsman's influence, and depicted Horsman retiring 'into what may be called his political cave of Adullam, to which he invited every one who was in distress, and every one who was discontented.' According to Bright Horsman's party, to which Bright's sobriquet of the "cave" has since adhered, consisted only of himself and Mr. Lowe, but thirty-three liberal members voted against the second reading of the bill upon which the ministry was afterwards defeated in committee (18 June). Horsman maintained his independent attitude to the last. He best served the public by exposing jobs and other weak points in the ecclesiastical system. In 1841, while he was a junior lord of the treasury, he gained notoriety for attacking Lord John Russell's ecclesiastical policy in 1847 and subsequent years. In 1855, under Lord Palmerston, he was made Chief Secretary for Ireland, but resigned in 1857. He gradually took up a position as an independent Liberal, and was well known for his attacks on the Church, and his exposures of various "jobs". His name became principally connected with his influence over Robert Lowe, 1st Viscount Sherbrooke in 1866 at the time of Gladstone's Reform Bill, to which he and Lowe were hostile; and it was in describing the Lowe-Horsman combination that John Bright spoke of the "Cave of Adullam". In the 1867 debate on extending the franchise, he said in the House of Commons: "There is an irreconciliable enmity between democracy and freedom". Family Horsman married Charlotte Louisa, only daughter of John Charles Ramsden, MP, on 18 November 1841. He died at Biarritz, France, on 30 November 1876, aged 68, and was buried there on 2 December. Publications "Speech on the Bishopric of Manchester Bill", 1847, two editions. "Five Speeches on Ecclesiastical Affairs delivered in the House of Commons, 1847, 1848, and 1849". "Speech on the Present State of Parties and Public Questions", 1861. His views and assertions were criticised in "Mr. Horsman's Statement respecting the Horfield