Beaufoy was returned as Member of Parliament (MP) for Minehead (1783–1784) and Great Yarmouth from 1784 until his death. He was a staunch advocate of the repeal of the Test and Corporation Acts, which limited the civil rights of non-members of the Church of England. He voted for abolition of the slave trade on 18 April 1791, but on 25 April 1792 announced his conversion to gradual abolition, in the hope that ‘the conclusions of my understanding may ultimately correspond with the dictates of my heart’. He expressed his fear that ‘too precipitate a benevolence augmented, while it hoped to have diminished, the sum of human calamity’, claiming that a cessation of the trade must aggravate the plight of the existing slave population of the West Indies, and that if it spelt ruin for the planters, no other country would abolish the trade and thereby destroy its colonies. He chaired the committees' of the House which on 1 May 1792 reported in favour of gradual abolition. The 1792 Slave Trade Bill passed the House of Commons mangled and mutilated by the modifications and amendments of Pitt, it lay for years, in the House of Lords. Biographer William Hague considers the unfinished abolition of the slave trade to be Pitt's greatest failure.
