* Ireland could be left isolated if voters say no(Reuters) - Ireland's decision to put Europe's new fiscal treaty to a referendum could damage its credit rating as a rejection by voters would block the country's access to a second bailout, ratings agency Moody's said on Monday.
Prime Minister Enda Kenny last week called a referendum on the treaty to tighten budget rules in the European Union, with a vote likely to be held in May or June.
A rejection of the treaty would disqualify Ireland from tapping the funds of the European Stability Mechanism (ESM), the euro zone's permanent bailout fund, cutting off a potential source of funds once its EU-IMF bailout runs out at the end of 2013, the agency said.