The political ramifications of the changes made to Louth, Meath East and Meath West will force several TDs to consider shifting their political base.
Under the changes, Louth, predictably enough, becomes a five-seater in compensation for its large increase in commuter population in recent years.
Two districts, St Mary's and Julianstown, which are effectively suburbs of Drogheda and totalling 17,000 residents, will transfer from Meath East to Louth.
Newly elected Fianna Fáil TD Thomas Byrne, who lives in one of the affected districts, is likely to move. His place in Meath East may be taken by Fianna Fáil's Johnnie Brady, who will be put under pressure if he stays in Meath West once it loses 7,000 voters in his heartland area around Kells.
Fine Gael will be more confident that it can take a second seat in the expanded Louth constituency once it is increased to a five-seater.
The efforts to persuade the commission to re-establish Leitrim as a single constituency have failed.
The commission acknowledged it had received "the largest number of submissions" from people wanting a single constituency for Leitrim. "It was not possible, however, to identify an alternative to the present general arrangement of constituencies in the area which both met the concerns and had no other undesirable impacts," it said.