The Taoiseach is expected to move Mr Brian Cowen, Mr Micheal Martin and Dr Michael Woods to new responsibilities in tomorrow's reshuffle, which will see a junior minister elevated to Cabinet and possibly two backbenchers made ministers of State.
With Mr Cowen expected to become Minister for Foreign Affairs and Mr Martin to replace him as Minister for Health, Dr Woods is widely tipped to succeed Mr Martin in Education.
A minister of state - most likely Mr Frank Fahey or Mr Martin Cullen - would then be promoted to Cabinet to take on the Marine portfolio held by Dr Woods.
The Taoiseach is to have final discussions with colleagues and advisers today, and senior political sources would not rule out some last-minute change to his plans. While Mr Cowen's and Mr Martin's moves are regarded as almost certain, Dr Woods's move - while considered highly likely - has not been finalised and there is speculation about other changes.
The Taoiseach said yesterday there would be "a few changes at senior level of significance . . . I'm not in the business of making changes for the sake of it but there are a few useful changes we can make".
Mr Ahern is to meet the Government Chief Whip, Mr Seamus Brennan, in Dublin this morning and is expected to tell him he will not be promoted to Cabinet on this occasion. Mr Brennan had been tipped as one of the main contenders for promotion.
However, Mr Ahern is likely to say that Mr Brennan's successful relationship with the four independents who support the Government makes it difficult to promote him. Galway West Minister of State Mr Frank Fahey and his fellow junior minister Mr Martin Cullen from Waterford are now seen as the two contenders for promotion.
Mr Ahern is understood to have approached at least one other minister of state to see if he would make way for the promotion of a younger backbencher. This would allow him to appoint two backbenchers to rejuvenate the image of his Government team. However, it is not known whether he has had any success in encouraging one of his juniors to relinquish his post. Appointments at minister of state level are not expected to be made until next week.
Meanwhile, the Government yesterday initiated a significant reshaping of the Supreme Court, nominating Mr Justice Ronan Keane as Chief Justice and Ms Justice Catherine McGuinness and Mr Adrian Hardiman SC as Supreme Court judges. Two more retirements from the court - next month and in May - will bring two further appointments, thus changing the face of the nine-member court.
Mr Justice Keane, Ms Justice McGuinness and Mr Hardiman are all highly regarded and independent-minded people who may bring an innovative approach to the court. Mr Ahern said the court now consisted of "an exciting group of people" who would face "a difficult challenge".
The Government nominated Dr Roderick Murphy SC, who chaired the independent inquiry into sex abuse in swimming, to the High Court. District Court Judge Desmond Hogan has been nominated for appointment to the Circuit Court, and Mr David Maughan to the District Court. All judicial appointments are made by the President on the nomination of the Government.
The Government has also appointed Mr Dermot Gallagher as Secretary General of the Department of the Taoiseach from May 1st, replacing Mr Paddy Teahon who is retiring. Mr Gallagher has been Second Secretary General at the Department of Foreign Affairs since September 1997 and is a widely-experienced diplomat.