Opposition parties will seek to block the appointment of Mr Hugh O'Flaherty to the European Investment Bank this week on the grounds that he still has questions to answer about the Sheedy affair.
Fine Gael will join the Labour Party, the Green Party and others in questioning the decision of the Minister for Finance, Mr McCreevy, to nominate Mr O'Flaherty to the EU post.
The Government was prepared to impeach him as a Supreme Court judge only a year ago because his actions were regarded as "damaging to the administration of justice", as the Sheedy case had been re-entered for hearing in the courts.
Later, Mr Sheedy secured early release in a case involving dangerous driving causing death.
It is understood that while Mr McCreevy spoke to the Taoiseach, Mr Ahern, the Tanaiste, Ms Harney, and other ministers before announcing the nomination last Friday, Government advisers were not consulted.
Fine Gael will open a Dail debate tomorrow condemning the nomination on the grounds that Mr O'Flaherty refused to go before a Dail committee to explain his role in the Sheedy affair.
It will also draw attention to the special legislation that was rushed through the Dail to provide the former Supreme Court judge and his High Court colleague, Mr Cyril Kelly, with special pensions after their resignations.
Mr O'Flaherty will continue to receive the £40,000 pension in addition to a salary of £147,000 if his proposed role as a vice-president of the European Investment Bank is ratified.
A spokeswoman for Mr McCreevy insisted that the Sheedy affair had nothing to do with the nomination.
No reference was made to the matter in Mr McCreevy's statement of nomination. Instead, he dwelt on Mr O'Flaherty's "distinguished legal career".
The Tanaiste, Ms Harney, is expected to come under considerable pressure to justify her acquiescence to the nomination.
But the Coalition Government has already been assured of support from Independent South Kerry TD Mr Jackie Healy-Rae.
Last night, Government sources did not expect any change in the matter. There was "no problem" in relation to Mr O'Flaherty's qualifications for the job, it was suggested.
What was at issue was Mr McCreevy's political judgment in nominating him for the job.
The Fine Gael leader, Mr Bruton, insisted yesterday that the Dail had to be told, before Mr O'Flaherty got any new job, why he had resigned from the Supreme Court "in a way that prevented the Dail from finding out what lay behind the Sheedy case".
It was unfortunate for the judiciary and for all those involved, Mr Bruton said, that the reasons why such unusual things were done in the Sheedy case had never been explained.
"It is bad for the institutions of the State that so many questions remain unanswered . . .
"This week's Dail debate on Hugh O'Flaherty's appointment to the European Investment Bank must find out why, and on what grounds, he chose to resign from the Supreme Court rather than defend and vindicate himself openly in the impeachment proceedings in the Dail.
"Did anyone suggest this choice to him? Why did he make it? "The public may know some of what happened in the Sheedy case, but it has no idea why it happened. And until Hugh O'Flaherty testifies, we never will. That is wrong," Mr Bruton said.
The Labour Party leader, Mr Ruairi Quinn, who declared himself "staggered" and "flabbergasted" by the nomination, will support the Fine Gael motion when it is voted on in the Dail on Wednesday night.
Green Party TD Mr Trevor Sargent said the nomination added to public cynicism, provided evidence that the so-called "golden-circle" still operated and established that the Progressive Democrats endorsed this level of nepotism.