During the 1940s, Quill became chair of the Liam Mellows Branch of the Labour Party. In this capacity he proved to be an enemy of Michael O'Riordan. The branch had been established by former members of the Curragh Camp's Communist Group. O'Riordan had retrospectively asserted that Quill was imposed as chair to ensure that Labour in Cork City could control the new branch. O'Riordan also stated that Quill had made an attack on what Quill "called 'the Jew boys' of Cork". It was during this time that the ITGWU had disaffiliated from the Labour Party and the National Labour Party was established on the basis that communists were infiltrating the party. A report in the "Irish Press" suggests that the Administrative Council "had become aware that certain persons in Cork were engaging in activities which appear to be inconsistent with their membership of the Labour Party and accordingly they appointed a subcommittee to investigate the membership and administration of the Liam Mellows Branch". O'Riordan's son, Manus, would later refer to Quill as an "anti-Semitic red-baiting villain" who was responsible for O'Riordan's expulsion.