Sinn Féin's Pearse Doherty has lost an 11th-hour High Court challenge against the Referendum Commission ahead of tomorrow's vote.
Mr Justice Gerard Hogan said he was not in a position to pronounce that a statement by Commission chairman Mr Justice Kevin Feeney on the ESM was wrong or likely to affect the referendum result.
Deputy Doherty claimed that on May 3, Referendum Commission chairman Kevin Feeney got it wrong when he said that Ireland could have vetoed the ESM, but did not.
He argued the much-publicised comment benefitted the Yes campaign as it implied the horse had bolted, whereas Sinn Féin said that under the Constitution, the ultimate power to ratify the ESM rested with the Government.
Given the last-minute nature of the challenge, Mr Justice Gerard Hogan said it would be impossible for the court to express a definitive view at this juncture.
In the circumstances, he said he was not in a position to pronounce that Mr Feeney's statement was clearly wrong or likely to affect the referendum result, ending Pearse Doherty's last-minute challenge.
Gerry Adams said it had been a worthwhile court battle.
"On the very crucial point as to whether the Government has discretion as to the veto, the judge said that it would be impossible for this court to give a definitive view," he said.
"We take great succour from the fact that this case has informed the citizens."
Tánaiste Eamon Gilmore said the challenge had been a "last, desperate attempt by Sinn Féin to cast doubt on the independence of the Referendum Commission."