The family of murdered solicitor Pat Finucane have backed the Taoiseach's criticism of the British government's plan for a restricted inquiry.
Mr Finucane, 39, was shot dead in 1989
Bertie Ahern told the Dail that Northern Ireland Secretary Peter Hain is seeking a judge to head the inquiry.
However, Mr Ahern said this was proving difficult as the international legal community has advised its members against accepting the position.
Mr Finucane, a Belfast solicitor, was shot dead by the UDA in 1989.
It is one of the most controversial murders of the Troubles, with allegations of collusion.
His son Michael said prominent lawyers have already been critical of the British government's plans to carry out the inquiry under the Inquiries Act, which the family argues cannot establish the truth.
"Justice Peter Cory, who wrote the report recommending an inquiry into my father's murder, said no self-respecting judge could accept a position and that he would urge his colleagues on the Canadian bench to decline if offered," he said.
"Lord Saville, the chairman of the Bloody Sunday Inquiry, was quoted as saying he would not be prepared to preside over an inquiry if at his back was a minister making decisions."
In a statement on Tuesday, the Northern Ireland Office said the restrictions on the inquiry would only apply to the bare minimum necessary to protect national security and to fulfil the government's legal obligations.
It said the inquiry's conclusions would be made public, including whether or nor there was collusion.
Earlier this month, an all-party motion in the Dail - the Irish parliament - called for for the British government to hold "a full, independent, public judicial inquiry".
Judge Peter Cory, the retired Canadian judge who investigated several controversial NI murders, also recommended a full, public inquiry.
Mr Ahern told the Dail on Tuesday: "Secretary of State Peter Hain told me on Thursday that he was going ahead with his inquiry and that they are seeking a venue.
"I am told they have a venue for the autumn.
"They are also seeking a judge. I understand from international connections that they are having great difficulty getting a judge."
Mr Ahern said he did not believe the inquiry would satisfy anyone.
"It will take five years to do it and it will cost 50m euro, nobody will ever believe it, at least none of the people we must try to represent," he said.
"Perhaps some people in the United Kingdom will believe it, although I have my doubts about that too, especially where the legal profession is concerned."