By-elections loom after TDs take up seats in Brussels
Voters in parts of the country will be heading back to the polls for by-elections in October or November.
A number of Dáil vacancies are expected to arise as a result of the EU elections.
Former Tánaiste Frances Fitzgerald's election in the capital will leave a space in Dublin Mid-West.
In Cork North Central, Fianna Fáil's Billy Kelleher is on course to become an MEP. Dublin Fingal TD Clare Daly could be vacating her seat and her colleague Mick Wallace is in the running in Wexford.
A by-election has to be held within six months of vacancies arising.
However, the situation could be further complicated if TDs take the final seats in Dublin or Ireland South.
These positions are to be held in "cold storage" until UK MEPs finally leave the European Parliament when Brexit takes place.
It's expected the MEPs-in-waiting will be allowed to continue as TDs in the interim.
Fine Gael sources suggested Leo Varadkar will have a very big call to make as to whether he should hold the by-elections or bring the entire country to the polls for a general election instead.
Ministers are wary about by-elections as they are usually lost by the Government party, and the Taoiseach has not closed off the prospect of a general election.
"Obviously the instability across the water in relation to Brexit, we have to bear that in mind, and also whether we can get the votes to get a budget through," he said.
The Government has already indicated that it hopes to hold another referendum in October, possibly on giving a vote to members of the diaspora in presidential elections.