More than 20,000 Seanad election voting papers for the Trinity College and NUI constituencies have been returned undelivered because graduates are not at home to sign for the registered-posted envelopes.
Outgoing senator and Dublin University candidate David Norris said it was "shocking" that while some 8,000 graduates out of an electorate of 50,000 had voted, "almost the same number [ of ballots] have been returned, largely because the addressee was not available to sign for the registered envelope".
In the NUI constituency, which has 10 affiliated universities and colleges, some 14,000 ballot papers have been returned undelivered, while 21,000 graduates have voted from the current 103,000 electorate.
NUI and Trinity have each reissued about 500 ballot papers where requested or where new addresses have been supplied.
Senator Norris said it was "such a pity that people would lose the opportunity to vote because they are working".
It was "impossible for the university to track down every individual", and called for more publicity by the colleges to inform graduates about their ballot papers.
A spokeswoman for Dublin University said its Seanad electoral office "will consider engaging in an advertising and media campaign requesting graduates to notify the office of their change of address for including in the next annual edition of the register of electors".
She added that every year the university sent all candidates for degrees and higher degrees a form to be completed for inclusion on the register of electors.
The spokeswoman said the university was "committed to ensuring that personal data held for an individual is accurate, complete and up-to-date".
NUI candidate Linda O'Shea Farren said it was a bigger problem because she believed the NUI register was totally inaccurate.
She believed the current electorate of 103,000 was 67 per cent inaccurate because of incorrect addresses. She also believed the actual NUI electorate should be 250,000.
O'Shea Farren, a solicitor, has expressed her concern to the NUI electoral office about its statutory obligation to update the register each year, rather than delegate its responsibility to NUI colleges to circulate forms to graduates.
NUI registrar Dr Attracta Halpin insisted, however, the register was updated annually. "We take all the steps we can to ensure students are registered."
She added that "it's totally voluntary for students to register".
She said all NUI colleges were autonomous, and "we're quite happy students in all the colleges are provided with forms to register".
