N'Jie first stood for election in the Legislative Council in 1951 but was not elected. He stood again in 1954, supported by his recently-established United Party. He had greater financial resources at his disposal than his opponent and had the advantage of not being associated with the unpopular incumbent Governor of the Gambia, Percy Wyn-Harris. He also enjoyed support from female voters who were organised by his sister, Yadicone N'Jie. N'Jie won the election and was also appointed to the Executive Council as Minister for Education and Social Welfare. However, in October 1955, following a clash between United Party supporters and Gambia Muslim Congress supporters in Bathurst, N'Jie accused the Chief Superintendent of Police of not taking enough action to prevent the violence and suppressing possible prosecutions. A subsequent commission of inquiry failed to support his accusation and strongly criticised his conduct. Wyn-Harris instructed N'Jie to resign from the Executive Council, and when he refused, he was dismissed in January 1956.