Dara Murphy, the Fine Gael TD for Cork North Central, is to resign from the Dáil in December to take up a senior position with the European Commission.
Mr Murphy is to take on one of the two top roles in the Cabinet of the incoming EU Commissioner on Youth and Innovation, Mariya Gabriel.
His departure from Irish politics would normally trigger a byelection, to take place within six months of his resignation. However, because the general election is widely expected to take place before the end of May, there will be no need for the Government to move a writ for a byelection.
Cork North Central is one of four constituencies where byelections will take place later this month. The current vacancy was caused by the election of Fianna Fáil's Billy Kelleher to the European parliament last May.
Ms Gabriel, who is from Bulgaria, has been a commissioner since 2017, and had responsibility for digital innovation. The new president of the commission, Ursula Van der Leyen, has asked her to take over a new portfolio. Mr Murphy will be a key member of her team.
While nominally a TD for Cork, Mr Murphy has been based largely in Brussels for the past two years, where he had a senior role with the European People’s Party (EPP). He has the lowest attendance record in the Dáil and is rarely seen in Leinster House. He had already announced he would not be contesting the next election.
The EPP is the centre-right group in the EU, to which Fine Gael is aligned. Ms Gabriel has been a vice-president of the EPP for several years.
However, now that he will have a formal position with the commission, Mr Murphy will have to step down as a representative politician. It is expected he will resign as soon as Ms Gabriel is formally ratified as a commissioner in early December.