"[3][4] In 1989, with the government's plan to reorganise and privatise electricity generation, the position of Chairman of the CEGB disappeared.

Marshall then entered into several jobs in the private sector connected with the nuclear industry and died in 1996.

As a scientist, Marshall was recognised as one of the leading theoreticians in the atomic properties of matter and characterised by his penetrating analytical powers.

In 1981 he chaired a Task Force, set up with representatives from major interested parties to evaluate the basis for the Sizewell B Design of nuclear power station.

[7] For his success in keeping the country's “lights on” during the protracted miners’ strike of 1984–5, Margaret Thatcher rewarded him with a life peerage and he became Baron Marshall of Goring, of South Stoke in the County of Oxfordshire on 22 July 1985.