The Council of State met today to examine legislation requiring elderly people to pay some of their nursing home bills, but deferred a decision until tomorrow.
On Sunday night, the President, Mrs McAleese, announced that she had summoned the Council of State to meet to discuss the Bill.
Under the Constitution, the President has until Friday to sign the legislation or refer it to the Supreme Court to decide if it is constitutional.
Following the council's meeting, the President has absolute discretion to refer the legislation to the Supreme Court to get a judgment on its constitutionality. A spokesman for Mrs McAleese said tonight that she could announce her decision "as early as tomorrow".
The Health Amendment (No 2) Bill was published last Wednesday and quickly passed all stages in the Dáil and Seanad on Thursday. Under the change, charges on elderly patients in State nursing homes and in private nursing home beds hired by health boards "are and always have been lawful".
The President has called only three previous meetings of the Council of State - which renders "aid and counsel" at her request - to offer advice on the constitutionality of legislation.
Yesterday, Opposition parties welcomed the President's decision, with Labour's health spokeswoman, Ms Liz McManus, saying her party had written to the President on Friday recommending such a move.
The emergency legislation was produced after the Attorney General, Mr Rory Brady, warned that deductions from pensions for nursing home care were not lawful under existing law.