Under Article 53 of the Free State constitution the role of the Vice President was to "act for all purposes in the place of the President", until the appointment of a successor in the event of his death, resignation or "permanent incapacity", or until his return in the event of his "temporary absence". However in practice the Vice President also held a second ministerial portfolio the duties of which he carried out when not called upon to become acting head of government. The Vice President could not be dismissed by the President. Rather, as was the case with all other cabinet ministers, for him to be removed from office the entire cabinet had to be dismissed and reformed en bloc.
The office of Vice President of the Executive Council was established with the establishment of the Free State in 1922. Neither of the two administrations that preceded the Free State, the Ministry of the Irish Republic and the Provisional Government of Southern Ireland, included an office corresponding to deputy prime minister. In 1937, when the new Constitution of Ireland came into force, the office of Vice-President of the Executive Council was replaced with that of Tánaiste.