Candidates placed in reserve and who will not take up their seats in the European Parliament until Brexit takes effect are not expected to receive a salary until they formally become MEPs.
Ireland has 11 outgoing MEPs across its three constituencies but has been allocated two more due to the UK's departure from the European Union.
Dublin will increase from a three- to a four-seater. Ireland South – which takes in Carlow, Clare, Cork, Kerry, Kilkenny, Laois, Offaly, Tipperary, Wexford, Wicklow, Limerick and Waterford – increases from four seats to five.
Midlands North West – comprising Leitrim, Monaghan, Donegal, Cavan, Louth, Galway, Roscommon, Mayo, Sligo, Kildare, Meath, Longford and Westmeath – remains a four-seater.
It was initially expected the UK would leave the EU on March 29th, but provisions were made for Brexit to be delayed and for the UK to take part in the European Parliament elections.
If the UK has not left the EU by the elections, with polling day in Ireland on May 24th, Dublin will initially elect three MEPs, with four each in Ireland South and Midlands North West.
Legal challenges
The fourth- and fifth-place finishers in Dublin and Ireland South will be placed in reserve. However, the counts in Dublin and Ireland South will be run in the same manner as four- and five-seat constituencies are usually counted.
Minister for Housing Eoghan Murphy this week said: "There will be one count – one count in Dublin for the four seats and one count in Ireland South for the five seats."
Concerns have been raised, however, about potential legal challenges on the basis that a different dynamic would apply if the constituencies were counted as three- or four-seaters.
Mr Murphy does “not expect” those placed in reserve “will be getting a salary or any benefits” but added work is continuing on how they may visit or participate in the European Parliament in that period.
If a TD is elected to the European Parliament, Dáil byelections must usually be held within six months of such a TD being declared elected as an MEP.
If Brexit is delayed, the six-month countdown will instead begin from the day the European Parliament first sits – July 2nd. If a TD is one of the two reserve MEPs, the six-month countdown will only begin at the point they take up their European Parliament seats.