The Government is seeking legal advice from the Attorney General, Mr Rory Brady SC, to ensure that ministerial orders to trigger use of the electronic voting system in the June elections will not be subject to constitutional challenge.
The move came as the Minister for the Environment, Mr Cullen, promised to withdraw leaflets publicising the system which included a picture of a vote being given to a Fianna Fáil candidate.
The Tánaiste, Ms Harney, said in the Dáil that the Government had to consult with Mr Brady to ensure that ministerial orders had the "required constitutional status" in light of a recent High Court judgment.
The court ruled last month in the case of the M50 motorway development at Carrickmines Castle that secondary legislation - such as regulations or ministerial orders - could not be used to amend primary legislation.
However, Mr Cullen's Department was still insisting last night that it will proceed with the introduction of the €35 million system in every polling booth in the State in the European and local elections.
A spokesman for Mr Cullen's Department said it was satisfied that ministerial orders made under Section 48 of the Electoral Act would be legally watertight because similar orders had been used in previous polls.
But Labour's environment spokesman, Mr Eamon Gilmore, said it followed from that decision that ministerial orders under the Electoral Act will be open to constitutional challenge in the courts.
"In these circumstances it would be an act of folly to insist on the use of electronic voting in elections that are now less than five months away," he said.
Mr Gilmore was speaking after a meeting of the Oireachtas environment committee at which the junior minister in Mr Cullen's Department, Mr Pat "the Cope" Gallagher, said that some of the software in the counting system was still being tested. He did not explain what aspect of the software was under scrutiny.
The spokesman for Mr Cullen's Department said 1,000 leaflets had been produced with a picture showing a vote being given to Fianna Fáil. He attributed this to an "oversight".
The Department will also amend a website page which showed a range of candidates from every party except Fine Gael, the spokesman said.