Taxpayers face an ongoing €1.2bn annual interest bill for the money dropped into Anglo Irish and Irish Nationwide, the first authoritative survey of the costs of the Irish banking crisis will reveal.

John FitzGerald, research professor at the Economic and Social Research Institute (ESRI), said taxpayers would not get a cent back from the €25bn swallowed by the nationalised Anglo and government-supported Irish Nationwide, and would run up €1.2bn in debt service charges each year to pay for the additional national debt.

The ESRI is preparing to release its latest quarterly report on the economy which will be eagerly awaited to see if it will support the government's view that the economy is stabilising.

FitzGerald said that the combined bill for the economic slump and the banking crisis would cost 10% of annual GDP, the equivalent of the country losing a year's economic output over the decade.

"Every penny that goes into Anglo, there is no upside in that. It is hard to see them getting anything back from that," he said.

Meanwhile, Chris Pryce, the influential credit rating director at Fitch Ratings, who helps determine the credit ratings for both Ireland and Greece, said that Nama was the "right thing" for the country. Despite Anglo Irish generating more losses than expected, there would be little impact and Ireland's credit rating was likely to remain unchanged "at this stage", he said.

Pryce said there was a possibility that Nama would pay AIB and Bank of Ireland more for their second and subsequent tranches of loans as the bad bank works through their commercial property portfolios.

He said it was important that the banks were allowed to work "professionally" without facing political demands from politicians.

"If Anglo had not existed then the other four [lenders] would have come in a little bit better.

"But Anglo does exist and the debt to the government will rise, not this year, but in the following years," he said.

The administration of Quinn Insurance was not a particularly significant development for international holders of Irish sovereign bonds, he said.

"It is significant that the new Financial Regulator is prepared to shine lights into corners. The amount of money is not a large development," Pryce said.

The investment world believes Ireland was doing "the right thing" and that "the government can be trusted to do the right thing", he told the Sunday Tribune.