[2][3] The UCPA's development as a black power organisation was driven by Stokely Carmichael's July 1967 visit to Britain, where he spoke at the Dialectics of Liberation Congress in London.
[2] Leadership of both UCPA and the British Black Panthers was later taken up by Altheia Jones-Lecointe, who joined the association after earning her Ph.D. She was able to revive both organisations which saw an increase in their membership.
[7] Plagued by in-fighting from its inception, the UCPA split up when most of its members opted to form a new organisation called the Black Unity and Freedom Party (BUFP) on 26 July 1970.
The inclusion of all non-white people as "black" was in line with their conception of imperialism, which declared that the world was being driven into two camps consisting of the imperialist and predominantly white Western powers on the one hand, and those of Asia, Africa, the Caribbean and the Americas on the other.
Roy Sawh's speech at Speaker's Corner in which he described black power as the "destruction of the white man’s society" was observed by two Special Branch officers of the Metropolitan Police (Detective Sergeant Francke and Detective Sergeant G. Battye) and the evidence they gathered was used to charge Sawh with "incitement to racial hatred" under the Race Relations Act 1965.