The Irish Government is facing heavy criticism over a deal to compensate victims of clerical abuse.
Ahern is accused of underestimating costs
Prime Minister Bertie Ahern and his ministers are being accused of hugely underestimating the cost of pay-outs to people who suffered sexual and physical abuse in the Catholic Church's institutions.
The row centres on a deal struck last year between the government and the Church.
It covered compensation for the thousands of victims in homes run by religious orders between the 1930s and the 1970s.
The Church agreed to pay around 130 million euros ($152m), which at the time was thought to be about half of the estimated bill.
But a report from Ireland's auditor-general suggests there could be up to 11,000 compensation claims leading to a total bill of around one billion euros ($1.1bn).
The BBC's James Helm said the whole issue of clerical abuse has been a long-running trauma in Ireland.
In the deal over compensation, the government agreed to indemnify the religious orders against further claims.
In heated exchanges in the Dail, the Irish parliament, opposition politicians said that taxpayers would end up paying for the shortfall, and Mr Ahern's government was accused of recklessness.
Enda Kenny, the leader of Fine Gael, the largest opposition party, called on the government to go back to the religious orders and tell them that they have a moral obligation to pay more of the bill for compensation.
Mr Ahern defended his government's record on compensating victims saying the agreement had been in the best interests of the victims and of the state - who had not wished to bankrupt the religious orders.
"The matter was not a simple one," he said. "I believe it was the right decision."