Tánaiste [ ˈt̪ˠaːnəʃtʲə ] (pronounced "Ta-nisch-te" ; pl. Tánaistí ; mostly with an article to Tánaiste ) is the title of the Irish Vice Prime Minister and representative of the Taoiseach . The official Irish salutation is a Thánaiste [ əˈhaːnəʃtʲə ]. The Tánaiste is appointed by the Taoiseach and must be a member of the government and a member of the Dáil . The word Tánaiste comes from the Irish Táinste and has historical origins as the name of the heir of a Celtic "chief" or "chief".
The Tánaiste is the representative of the Taoiseach in the event that the Taoiseach is temporarily unable to exercise his office. In the event of death or a circumstance due to which the Taoiseach can no longer exercise his office, the Tánaiste takes over his duties until a new Taoiseach is installed. The Tánaiste, whose title is largely an honorary title, comes from the ranks of the ministers and is an ex officio member of the Irish Council of State . In the case of a coalition government, the Tánaiste usually comes from the second largest coalition party; in one-party governments this office is often taken over by an older generation politician as a sign of recognition.