[1] At the factory he became in involved in union work and also got engaged in the Swedish Social Democratic Youth League.
In 1958 he became secretary in charge of negotiating wages and working conditions in the metal industry around the country.
[1] A dedicated socialist, Lundin at the conference of the Swedish Trade Union Confederation in 1976, advocated for a more radical version of employee funds for collective ownership of companies than Rudolf Meidner had proposed.
[4] After he left the leadership position of Metalworkers' Union, he led the Labour Movement's International Center, today Olof Palme International Center and in that capacity he continued to work with the Chilean opposition, including later president Ricardo Lagos.
[4] In his older days, he was involved with the metalworker's building at Skansen museum where he organized study circles.