Ireland will remain at severe risk under Europe's sovereign debt cloud "for years", with the cost of servicing the national debt here likely to climb even more next year, a leading sovereign debt commentator warned this weekend.

Luca Cazzulani, senior strategist at Unicredit in Milan, said that Irish sovereign interest rates will probably rise toward 5% next year even if markets "calm down" over the debt challenges facing Greece, Portugal and Spain.

He said he expected the European Central Bank to start preparing markets for a rise in interest rates next year, a move which would have a knock-on effect in pushing the sovereign interest rates Ireland must pay to service its national debt even higher.

Ireland would continue "for a couple of years" to be part of the group of four European countries, including Portugal and Spain, that markets will perceive as being the most vulnerable. Bond-holders would, therefore, continue to demand Ireland pay higher sovereign interest rates as an insurance policy against the perceived greater risk of the state defaulting on its repayments to international lenders, he said.

"The fact is we have these four countries that have proven to be weak under different cirumstances. Greece will remain perceived as a weak country for longer. Then you have Spain and Portugal," Cazzulani said. "I think Ireland is in the best position among the group of four." Meanwhile, Fitch Ratings, one of the world's three largest credit rating agencies, will deliver better news when it publishes revised Irish national debt figures in June, the Sunday Tribune has learned.

Fitch director Chris Pryce, who helps set the credit ratings for both Ireland and Greece, said its updated forecasts will show Irish debt peaking at a lower level next year than it first thought. The decision by the government to fund the €20bn Anglo Irish needs by issuing €2bn in so-called promissory notes each year over the next 10 years will reduce by €18bn the debt Fitch had calculated the government would need to borrow immediately from markets this year.

Fitch now sees the government debt pile here, including the banking loans purchased by Nama, peaking next year at about €180bn, down from the €200bn it first forecast.

"I think it will have some market impact. Our latest forecast is 103% of GDP for Ireland this year and we see it rising only 4% next year and even possibly coming down a bit the following year," Pryce said.

Cazzulani in Milan said that both Spain, which faces scrutiny amid fears that bad loans will mount at its banks, and Portugal, which has to raise €25bn from markets this year, would remain under the severest pressure in the coming months.

"Portugal has to issue a lot of debt this year. It is the thing that worries me the most," he said.

Irish sovereign rates last week remained at a high levels even following the agreement to launch separate multibillion-euro bailout funds for Greece and the rest of the eurozone.