There he set up a small publishing company called Karia Press, based in east London, producing books relevant to community and race relations, and making available and better known the work of many key writers, including Claudia Jones, whom he is credited with having "rediscovered".
[3] He won a scholarship to continue his studies as a mechanical engineer in Britain, where he migrated in 1971,[5][6] living in London variously in Stoke Newington, Clapton and Homerton.
Karia managed to more than hold its own alongside John la Rose's New Beacon Books, Eric and Jessica Huntley’s Bogle L'Ouverture, Allison and Busby, and Karnak House, the other pioneering black publishers.
Johnson continued his concern with the struggles of Black people in Britain and elsewhere, as Chris Searle has written: "I first met him when we were both involved in the campaign to free the trade union militant and organiser of the unemployed, Desmond Trotter of Dominica, who had been framed on a murder charge and condemned to hang by the neocolonial government of Patrick John, much dominated by the Geest and Cadbury/Schweppes monopolies which owned most of the island's banana, cocoa and citrus plantations.
We worked closely with Liberation (formerly the Movement for Colonial Freedom) and frequently met at its north London office in Caledonian Road.... Trotter was eventually reprieved and released, largely through intense international pressure, in April 1976.