Minister for the Environment Dick Roche has said that some "inadvertent deletions" have been made during the compilation of a draft electoral register in recent months and he urged voters to check that they are included on the new list.
The draft was finalised in each of the State's local authority areas last Wednesday and the Department of the Environment expects to receive full figures from each this week.
It is the result of a €12 million campaign aimed at removing up to 800,000 duplicate and inaccurate names on the current register, and a final version is to be completed by November 25th.
"The efforts to radically reform a woefully inadequate register inevitably mean that some inadvertent deletions have been made," Mr Roche told the Fianna Fáil ardfheis on Saturday.
"I ask you to use the next three weeks to ensure that people who should be on the register remain on the final register."
Initial data supplied by county councils shows that significant changes have resulted from the campaign, which involved 1,500 field workers calling to each household in the State over several months.
In Co Louth, the voter register has increased from 88,443 to 92,177, with 11,890 voters having been removed because their names could not be confirmed at the given address.
In Co Meath about 23,500 people were removed, although the council expects to add some 10,000 more.
However, a spokesman for the department said it was too early to calculate how many legitimate voters had been removed from the list as it had not yet received figures from local authorities.
"We haven't got the full picture yet. The department are going to be receiving the figures over the next few days, but at the moment people are dealing with incomplete figures."
The spokesman also rejected newspaper reports that its guidelines on the compilation of voter data were being inconsistently applied, saying it had "no information" that the "strict procedures" it laid down for local authorities were not being followed.
"Each household in the State was visited and provided with forms at least twice. In the event that no satisfactory response was received, written notification was then given cautioning of the danger of being removed from the register," he said.
"The procedures are fairly extensive, and we have gone into great detail to ensure that this register is right. The Minister has devoted a lot of time and a lot of resources to make sure that this is done."
Voters have until November 25th to ensure that they are included on the register, and should report errors or omissions to their local authority. There will also be an opportunity to apply for inclusion on the supplementary register up to 14 days before polling day.
Copies of the draft registers are available in libraries, Garda stations and civic offices, and can be viewed online at www.checktheregister.ie
Mr Roche's spokesman said the Minister would look into the use of biometric fingerprint scanners or having people dip their thumbs in indelible ink to prevent electoral fraud, but neither would be considered for the next election.