Born in Halifax, Stansfeld was an early supporter of the Chartist Movement. Elected to parliament as MP for Halifax in 1859, he consistently supported radical causes and championed the state movements across Europe, numbering Giuseppe Mazzini and Garibaldi amongst his friends and moving a resolution of sympathy with the Poles in the House of Commons. His alleged support for groups campaigning against Napoleon III led Disraeli to accuse him of ‘being in correspondence with the assassins of Europe’. Stansfeld served under Palmerston and Russell and entered the cabinet in 1871 as President of the Local Government Board. From 1874 Stansfeld devoted his energies to the repeal of the Contagious Diseases Act and refused further office until the Act was repealed in 1886. He then returned to the Local Government Board in Gladstone’s short-lived third administration.