Sinn Féin is to seek legal advice on whether the Government's information campaign on the fiscal treaty referendum is in breach of the McKenna judgment.
That judgment, delivered in 1995, said the Government is not allowed to use public funds to advocate one side in a referendum campaign.
This evening, Sinn Féin said it believed the Government was in breach of the McKenna judgment by using public funds for its "so-called information campaign".
The party said it was important that people receive independent and unbiased information so that they can come to an informed judgement on polling day.
A Government spokesperson said the publicly funded campaign provided information, not advocacy, and they were satisfied that it complied with the McKenna judgment.
The Government has already set up a website - www.stabilitytreaty.ie - and has approved a booklet for delivery to every home in the country over the next week.
The 40-page booklet gives the text of the treaty and an explanatory memorandum, in both English and Irish.
A further Government mailing is to be sent to every home in the country later in the campaign.
The Government information campaign is in addition to the work to be carried out by the Referendum Commission.
Meanwhile, a senior IMF official has said that adopting the fiscal treaty does not mean permanent austerity.
IMF deputy divisional chief Xavier Debrun told RTÉ News that once a government had a more balanced budget situation then belt-tightening was no longer necessary.
Mr Debrun said the treaty simply meant that governments adhered to "common sense" housekeeping rules.
He said Ireland passing the fiscal treaty would improve the country's chances of returning to the international markets to borrow.
Mr Debrun said: "Fiscal rules are about fiscal responsibility, the fact that over the long-term governments make sure that on average they can pay for the policy measures they implement. This is just common sense.
"This is called the budget constraint: you are subjected to it, I am subjected to it, the government is subjected to it."
Speaking after an event in Brussels, Mr Debrun said austerity was caused by governments ignoring the budget constraint and then being faced with fiscal shocks which required belt-tightening.
He said: "The belt-tightening is the austerity, but you do not have to tighten your belt forever, obviously."
Elsewhere, economist Colm McCarthy believes a No vote in the referendum could diminish Ireland's chances of getting a second bailout.
Mr McCarthy said if you believe that Ireland can get back into the bond markets next year and there is no chance it will require further funding, then the vote does not matter either way.
However, he told RTÉ's News at One that he believes it is "on the cards" that Ireland will need extended financing.
Mr McCarthy said regardless of the outcome of the vote, there will be further cuts.
He said: "There is no scenario in which we can avoid getting the budget deficit under control."
In the Dáil, Taoiseach Enda Kenny asked Sinn Féin leader Gerry Adams to explain what Sinn Féin's alternative was and what would be the consequences of a No vote.
Mr Kenny asked where Sinn Féin would get the money to run the country.
Mr Adams said the Taoiseach's constant invoking of the train metaphor was fine, but the train was going in the wrong direction.
People Before Profit TD Richard Boyd Barrett said that recent and ongoing protests in Ireland are part of a huge number of protests in many other countries.
Gilmore calls on workers to vote Yes
Tánaiste Eamon Gilmore has said it a matter for union executives whether to endorse a No vote in the referendum, but he said he was calling on individual workers to vote Yes.
Mr Gilmore said he respected the right of unions to give advice to their members, but he said every worker is paid in euro and the stability of the euro was important to workers and to pensioners.
He said it was important to public sector workers that Ireland had access to emergency funding if necessary.
Minister for Finance Michael Noonan said that the advice of unions to members to vote No was, in general terms, bad.
Mr Noonan said their primary concern should be to protect jobs and a No vote could put jobs at risk.
Some unions have already announced their position.
The TEEU, Unite and Mandate are all urging their members to vote No in the upcoming referendum.
The executive council of the Irish Congress of Trade Unions will meet tomorrow to consider its stance on the treaty.
Meanwhile, the Seanad has passed the legislation paving the way for the referendum without a vote.
As less than five members stood against the Bill's passage, it went through the final stages without a vote being called.
The Bill now goes to the President.