 At the end of 1974, Alf Dulson retired as general secretary of the union, by then renamed as the Ceramic and Allied Trades Union, and Sillitoe won the election to replace him.He had immediate success by securing a closed shop agreement with the British Pottery Manufacturers' Federation, agreeing how future wage increases would be calculated, and secured an extra two days holiday for workers in the industry.This agreement took the union to its highest ever membership density, with more than 75% of eligible workers joining.