Under pressure from the anti-slavery interest in the House of Commons, the British Government undertook, in 1823, to reform West Indian slavery and prepare the slaves for eventual freedom. This policy of amelioration was based on the assumption that the West Indian planters would co-operate with the British Government to improve slave conditions. As George Canning explained to the House of Commons, ‘The masters are the instruments through whom, and by whom, you must act upon the slave population.’ Ten years later the reform programme was abandoned in favour of abolition. This change of policy reflected, in part, the conversion of officials at the Colonial Office who began to urge the need for emancipation in 1831. For eight years the Colonial Office made persistent efforts to induce the co-operation of the West Indian planters; these attempts failed and a mass of evidence accumulated which suggested that the slave system could not be improved, it could only be abolished. This article demonstrates the efforts made by the Colonial Office to effect amelioration in the legislative colonies with particular reference to Jamaica and the nature of the evidence which demonstrated that emancipation was the only viable solution to the problem of West Indian slavery.