The euro surrendered gains to trade little changed against the dollar today after Taoiseach Enda Kenny said Ireland will hold a referendum on Europe's new fiscal treaty.
It will be the first vote on the German-led plan for stricter budget discipline across the European Union.
The euro weakened to as low as $1.3389 against the dollar after the announcement, before recovering to trade at $1.3416.
"A vote against the euro zone fiscal pact would block Irelan from the euro zone bailout fund," said Christopher Vecchio, currency analyst at DailyFX in New York. "European leaders have warned that a 'no' vote would be a symbolic rejection of euro zone membership."