Standard & Poor's downgrade of Ireland's credit rating was "inevitable", and other ratings agencies are likely to follow suit, says Schroders.
Roger Doig, a credit analyst at the group, expects other agencies will begin to look at their grades after GDP expectations in Ireland were revised.
There is also potential for Irish banks to need even more help in the future, he adds, causing agencies to further review their ratings.
"The existing programme for the bailout of the banks addressed the commercial property developers, which is the worst part of the Irish bank books. Nothing has been added to the residential issues on the mortgage book, these sit on the banks' own balance sheet and are dealt with by the banks' own accord," he says.
"They are managing to deal with these losses through retained earnings but if there is a shock, such as further unemployment or rising eurozone interest rates, there is potential for the residential mortgage book to perform worse than it is currently. In this case the bailout could cost more."
S&P credit analyst Trevor Cullinan says Ireland's credit rating could be downgraded further if the financial sector continues to weaken.
"The negative outlook reflects our view that the rating could be lowered again, as a result of its support for the financial sector or due to a more sluggish economic recovery, the government's fiscal performance improves more slowly than we currently assume," he says.
Conversely, the rating could also be changed if S&P believes the Irish Government looks likely to achieve its fiscal target for the underlying deficit of less than 3% of GDP by 2014.
Cullinan says the reason for the downgrade was S&P's concerns over its projection that Government debt will rise towards 113% of GDP in 2012.
Ireland now has a rating of AA-, cut from AA, and the lowest since 1995.
"The downgrade reflects our opinion that the rising budgetary cost of supporting the Irish financial sector will further weaken the Government's fiscal flexibility over the medium term," Cullinan says.
Earlier this week the chief executive of Ireland's National Treasury Management Agency, a quasi-state institution that deals with debt auctions, hit back against S&P's decision.
John Corrigan said the ratings agency's calculations were "flawed" because they were not in line with the statistical approaches used by the IMF or Eurostat.
