There are fresh doubts over the passage of the Finance Bill through the Dáil, despite cross-party agreement to accelerate its progress.
Three independent deputies who normally support the Government have threatened to vote against the Bill.
Michael Lowry, Jackie Healy Rae and Mattie McGrath say they are opposed to some elements of the legislation.
The passage of the Bill is expected to be the final business of the 30th Dáil before the General Election.
Speaking on RTÉ's News at One, Mr Lowry said he was likely to vote against the Finance Bill if four outstanding issues of concern to him were not addressed.
He also said he originally committed to support a full Government with leadership, direction and economic policies, not a 'half Government'.
Mr Lowry said he had no 'obligation or responsibility' to support a dysfunctional Government.
He said 'too much had happened' and 'the charade and circus' that had gone on for weeks should be brought to an end.
Mr Lowry said in the past few months he has asked the Taoiseach twice to call a General Election.
Click here to read a statement from Michael Lowry
Mr Healy Rae said that his position on the Finance Bill was the same as that of Mr Lowry.
Mr McGrath said he has concerns about the Bill, which he hopes Minister for Finance Brian Lenihan can address.
'I am meeting the Minister for Finance about these issues, but at this point in time the Government can't rely on my support for the Finance Bill,' said Mr McGrath.
'I'm not happy with the Universal Social Charge; changes to PRSI; and changes to the assessment time for self-employed people who are making tax returns.'
Meanwhile, Minister Lenihan has said the Government is planning to bring amendments to the Finance Bill relating to the Universal Social Charge.
Click here to read Brian Lenihan's Finance Bill speech
The proposal is to introduce a lower rate for medical card holders, who will no longer be subject to the 7% rate over €10,000, but will pay 4% instead.
However, self-employed people will pay an extra 3% surcharge on incomes over €100,000. He said this would mean such people would be back before they were before the Budget.
The charge, introduced in the Budget, amalgamated the health and income levies. It had three rates - 2%, 4% and 7%.
Minister Lenihan said the change would apply for the lifetime of the four-year plan.
The cost of putting medical card holders on the lower rate of the charge would be €80m, according to the Minister. This is to be made up by the surcharge on the self-employed.
The 30th Dáil has begun what is expected to be its final week this afternoon, with all normal business cleared to allow for the passage of the Finance Bill.
It comes after an agreement was reached between Mr Lenihan and Fine Gael, Labour and the Greens.
The Bill is due to pass all stages in the Dáil by Thursday before going to the Seanad, with a General Election to be called by next Tuesday at the latest.
Meanwhile, Green Party Senator Dan Boyle said it is his understanding that a Finance No 2 Bill will be moved to deal with the financial provisions of the Civil Partnership Act.
He said the Bill would be passed by 1 April 1st and that it was part of the agreement at last night's meeting of finance spokespersons.
The 150 amendments dealing with the tax and financial provisions of the Civil Partnership Act are not being dealt with in the Finance Bill.