TAOISEACH Brian Cowen is thought to be planning a major cabinet reshuffle following the resignation of former Defence Minister Willie O'Dea.
Speculation about substantial changes has heightened in the wake of junior minister Conor Lenihan's comment that he expected a significant reshuffle by the middle of the year.
There was also speculation that Tourism Minister Martin Cullen could resign as a result of back problems. However, the minister's office rubbished these rumours.
Mr Cowen is under pressure from Fianna Fail backbenchers to carry out a radical reshuffle of the Cabinet.
Other ministers thought to be under the spotlight include Health Minister Mary Harney and Community Affairs Minister Eamon O Cuiv.
However, the Taoiseach would not be drawn on whether he would fill the Defence Minister's position this week or if he would opt for a wider reshuffle.
He said: "I said that I would retain the Department of Defence for the present and that's my intention but I wouldn't be signalling anything beyond that.
Green Party senator Dan Boyle insisted his party did not demand Mr O'Dea's resignation.
Fine Gael leader Enda Kenny said the Government was "falling apart from the centre" and does not have the moral authority to lead, adding that the credibility of the coalition was in tatters following the resignation of Mr O'Dea.
Despite the Greens' denial, it is believed the party insisted that Mr O'Dea had to go.
Mr Cowen asked the Green leader John Gormley to allow Mr O'Dea to resign "in his own time'' but the Greens said he had to stand down immediately.
O'Dea met with Cowen shortly after his disastrous RTE radio interview at lunchtime last Thursday. It is believed both men acknowledged that O'Dea would have to resign.
However, the defence minister had sought time to consult with family and friends over the time of his exit.