Ireland will elect 11 MEPs from three constituencies in the European elections next year.
Under the new boundaries announced this evening to take account the loss of a seat in the European Parliament Leinster is split in two by the measure.
The 11 MEPs will be elected in three constituencies - a three seater in Dublin and two four-seaters called Midlands North-West and South.
That South constituency comprises Carlow, Clare, Cork, Kerry, Kilkenny, Limerick, Tipperary, Waterford, Wexford and Wicklow.
While the Midlands North-West constituency is made up of Cavan, Donegal, Galway, Kildare, Laois, Leitrim, Longford, Louth, Mayo, Meath, Monaghan, Offaly, Roscommon, Sligo and Westmeath.
The abolition of the Ireland-East constituency - with it being effectively divided up between the other two big constituencies - and Clare re-united with the rest of Munster are the main changes.
Fine Gael Dublin Senator, Catherine Noone, has welcomed the announcement.
"Many counties have TDs which look after their concerns, or one single council, whereas Dublin is made up of many fragmented voices, which often look after their own bits of the city rather than having one holistic outlook for Dublin". she said.
"As such, I have always maintained that it’s vitally important for Dublin to stay on its own for the purposes of electing MEPs" she added.
Independent MEP Nessa Childers, has said that because her Ireland-East constituency has been merged into other constituencies, it means she will now have to give consideration to which new constituency she might contest.
While Sinn Féin have also welcomed the decision, saying they will be campaigning in the Midlands-Northwest constituency.