The Dail's newest member will take his seat in the chamber this afternoon, but while a newcomer to the Dail, former senator Pearse Doherty is no stranger to Leinster House.
However, the new TD for Donegal South West could serve less than ten weeks before a general election is called.
This afternoon, there will be scenes of jubilation as Deputy Pearse Doherty formally signs in as a Dail deputy, with a large contingent of family, friends and supporters in Dublin for day.
Before the festivities though, he will attend a press conference at which Party President Gerry Adams will outline Sinn Féin’s alternative economic analysis, and the Dáil group's intention to use its strengthened presence to do all in its power bring down the Government and force a general election.
Deputy Doherty becomes the fifth Sinn Fein member of the Dail, and if they can attract two Independent deputies who oppose the government into a technical group, they can receive enhanced rights, including the right to move motions of no confidence in the Taoiseach, which the party wants to do as quickly as possible.
The Greens remain adamant they want to see the budget and Finance Bill passed early in the new year, and an election called for the last week of January. Sinn Fein hope that the election of Deputy Pearse Doherty may see the budget defeated and the governemnt fall next week.