Businessman Declan Ganley has compared the European fiscal treaty to the doomed Titanic.
The political activist, who launched a poster campaign calling for a No vote in the referendum, said the deal would do nothing to solve the European bank debt Ireland must pay.
He also argued that the European Stability Mechanism (ESM) – the emergency fund available to member states in need of a bailout – will not be enough to help those in dire straits.
“This is like being offered a ticket for the Titanic and saying if you don’t get your ticket now, you’re going to miss the boat,” said Mr Ganley.
“That’s one boat that there is no harm in missing.”
His comments came after Finance Minister Michael Noonan insisted individual states must honour their commitments to Europe to ensure the eurozone remains intact.
Mr Noonan travelled to Brussels to take part in talks with other European finance ministers on issues including Greece’s future within the euro.
He said he would encourage Greece to form a parliament that is willing to implement a programme and that he would like to see the country stay in the euro.
“It’s very important that the eurozone stays intact,” said Mr Noonan.
Meanwhile, former European Parliament candidate Mr Ganley announced his plans to campaign for a No vote in the May 31 referendum over the weekend.
He said his campaign budget was €50,000 and any help he gets will be from volunteers.
The founder of Libertas, which is now known as a think tank, successfully campaigned for a No vote in the Lisbon Treaty referendum in 2008.
“The ESM is not the solution to Europe’s problems,” he went on. “It’s an exacerbation of a Ponzi scheme that is failing and that’s failing to a greater extent every day.”
The businessman launched his initiative just as the Labour Party stepped up its efforts to promote a Yes vote in the referendum.
With less than three weeks to go, Social Protection Minister Joan Burton argued that ratifying the treaty will ensure Ireland has access to the ESM.
She said Ireland would be walking a financial tightrope if it rejected the treaty, which aims to impose stricter budgetary rules to member states and drive down their deficits.
The latest Red C poll, published over the weekend, showed the majority of Irish voters support the fiscal treaty.
The portion of those planning to vote Yes on polling day increased six points to 53%. The remainder include those who are opposed to the treaty and voters who have yet to decide.