Ireland is likely to need a second bailout when its current aid program ends, rating agency Moody’s warned today.

In its weekly credit outlook report, Moody’s also warned a No vote in the upcoming fiscal treaty referendum would bar Ireland from receiving further funds under the European Stability Mechanism (ESM).

The agency predicted the Government would have to rely on the ESM for additional funding after the existing bailout program expires in 2014.

"We expect Ireland to face challenges regaining market access in 2013 and it will likely need to rely on the ESM, at least partially, when the current support programme expires,” it said.

Minister for Finance Michael Noonan is targeting a full re-entry to bond markets by the middle of next year, as the Government seeks to wean the State off international aid.

The National Treasury Management Agency (NTMA) plans to step up issuance of short-term bonds later this year in anticpation of a full return to the markets next year.

Moody’s warned, however, that rejecting the EU's fiscal treaty would make Ireland ineligible to access further ESM funding which would otherwise have provided the country with a credit-line until 2014.

Ireland's decision to hold a referendum on ratifying the compact was “credit negative”, Moody's said.

Separately, Citigroup economist Michael Saunders said investors face a 50 per cent chance of sharing in losses in Irish Government debt.

"We still expect a sizeable growth undershoot and deficit overshoot, and expect that Ireland will need a second financing package. . .  beyond 2013," Mr Saunders said in a weekly broker’s note.