There are calls for the Government to ensure the electoral register is fully updated ahead of next month's general election, amid fears thousands of newly-registered voters could be excluded.
Taoiseach Leo Varadkar is to dissolve the Dáil today, with polling day set for Saturday 8th February.
The polling date means thousands of people placed on the draft electoral register in the recent months won't be eligible to vote, as the updated register is not valid until February 15th.
While those impacted will still be able to be put on the supplementary register, they would have to register for a second time to guarantee their vote.
Concerns have been raised that the law regarding the register cannot be changed now as the Dáil is to be dissolved.
There are calls for Government ministers to now issue immediate guidance to local authorities to automatically transfer all new registrations to the supplementary register.
Solidarity TD Mick Barry warned that the situation is a potential disenfranchisement scandal "that must be averted".
Speaking on the Pat Kenny Show, meanwhile, Fianna Fáil leader Micheál Martin said this situation should have been anticipated.
He argued: "Irrespective of who they might vote for, my view is the right thing to do in terms of democracy is to facilitate and make sure that they will be able to vote.
"We believe in participation and democracy and in the voting process."
Sinn Féin Housing spokesperson Eoin Ó Broin TD argued: “There appears to be some confusion in Local Authorities over whether these voters can automatically be placed on the supplementary register by the Council or if they have to re-apply to go on the supplementary register.
“The Department must issue clear guidance on this matter to ensure that no person is denied the right to vote because Varadkar decides to call an earlier than expected general election."