His first posting was to the Board of Trade where he investigated social issues such as cost of living, rent and housing conditions in England and Scotland.
Phelan wanted to see the world, so he resigned his secure job and began to work for George Lunn Tours Ltd. a tourist agency with headquarters at Lugano, Switzerland, near the Italian border.
The outbreak of the First World War ensured the suspension of the enquiry and he was instead assigned to the newly established Ministry of Labour at Montagu House, Whitehall.
Phelan accompanied Bruce Lockhart as the first British delegation to meet the Bolsheviks in Moscow in January 1918, just as the Finnish Civil War commenced and coincidental with the Brest-Litovsk negotiations.
A few months after the signing of the Versailles treaty and prior to its ratification, Phelan and Harold Butler organised the inaugural meeting of the ILO in Washington.