Brother McLermon was elected President of the Canadian Union of Transport Employees (UCTE) at its first component convention in 1969. In 1959 John was elected Vice-president of the Toronto Meteorological Branch of the Canadian Air Services Association (CASA). In 1958 he was elected Branch President. In the early 1960s, he edited the branch newsletter “Headquarter Hi-Liter.” At the 1962 convention of the CASA, he was elected Regional Vice President, a position he was re-elected to in 1964. He participated in the 1966 merger meeting of the Canadian Marine National Employees Association (CMNEA), the Canadian Air Service Association (CASA), and the Civil Service Association of Canada (CSAC), which created the Department of Transport Component (DTC). At that meeting, he was elected Ontario Regional Vice-President of the component. In 1969 at the first component convention, he was elected president of the newly named UCTE. In 1971, Canada created the Department of the Environment. When this happened, the new ministry incorporated UCTE members working in the Meteorological Service of Canada (established in 1871), which was where John was employed. He resigned as president before completing his term of office.