Geert Vanden Wijngaert, Associated Press
Irish Prime Minister Enda Kenny, left, arrives for an EU summit in Brussels on Thursday, Dec. 8, 2011. During a two-day summit German Chancellor Angela Merkel and French President Nicolas Sarkozy will try to build support for their plan for eurozone nations to submit their national budgets to much greater scrutiny.

DUBLIN — Ireland's prime minister said he was unsure whether the European Union's new agreement to bolster the eurozone will require approval in a national referendum.

The country has been a prominent stumbling block in enacting European agreements because, unlike other EU members, Ireland typically subjects them to public votes.

Irish voters rejected the union's previous two treaties in 2001 and 2008, delaying ratification of both painstakingly negotiated pacts for years. In both cases, the government staged second referendums in 2002 and 2009 that overcame anti-EU sentiment.

When asked if he was confident of winning a referendum on the new eurozone agreement for closer fiscal union, Prime Minister Enda Kenny said he would need legal advice before deciding whether Ireland even needed one.

"Every country has to do its own thing," he said. "In our case, the attorney general will have to analyze that, forensically examine it, and give an official and formal advice to the government as to whether a referendum is required or not. Obviously, I wouldn't speculate on that because I wouldn't be competent to do so."

Attorney General Maire Whelan declined to comment.

Ireland's minister for European affairs, Lucinda Creighton, said she considered prospects of a referendum "50-50."

The Supreme Court ruled in 1987 that Ireland's constitution requires any proposed EU treaty to be ratified directly by the public, not just their lawmakers, if that treaty would "alter the essential scope or objectives" of EU institutions.

The opposition leader in parliament, former Foreign Minister Micheal Martin, criticized the government for claiming it doesn't know whether a referendum is needed this time.

"Clearly it has not analyzed what exactly will change under the new system," Martin said.

He warned that Ireland should be wary of endorsing any treaty that the United Kingdom has rejected as bad for business.

Like the U.K., Ireland opposes EU pressure to raise taxes, particularly on corporations. France and Germany have repeatedly criticized Ireland for taxing corporate profits at a rate of 12.5 percent, the lowest in Western Europe and less than half their own rates. The low rate has helped attract foreign multinationals that generate 18 percent of Ireland's economic output.

"We need immediate reassurance that there is nothing in the enhanced cooperation and control rules that could impact on the financial services sector or corporate taxation," Martin said.

Martin's party, Fianna Fail, represents center-ground opinion and is pro-EU.