Percy Johnson-Marshall was Honorary Secretary of the Coventry Branch of the Association of Architects, Surveyors and Technical Assistants (AASTA), while working for Donald Gibson's team at Coventry City Architectural and Planning Department. The Branch mounted a week long exhibition entitled "Coventry of tomorrow: towards a beautiful city" from 6-13 May 1940 . This was the culmination of a publicity campaign aiming to generate local enthusiasm for new plans of the city which had been created by Gibson's team. The ideas presented at the exhibition pre-dated the World War II bombing, which started on 14 November 1940 , which led to the requirement for comprehensive redevelopment plans for the city.
The AASTA became became the Association of Building Technicians (ABT) in 1942.