Kemp returned to his studies at LSE in 1946 and in 1950 joined the economics faculty of the University of Hull, where he taught for over 30 years.
He was the doctoral advisor of Gabriel Salazar, who had arrived to the University of Hull as an exile from the military dictatorship in Chile.
As a political activist Kemp was, together with Cliff Slaughter, one of the theoreticians behind the Socialist Labour League and the Workers Revolutionary Party.
Kemp was an important thinker and activist within the group and its successor organisations the Socialist Labour League and the Workers Revolutionary Party.
After Healy’s expulsion from the party in 1985 Kemp resumed an active role in WRP, continuing until his death in 1993.