The Dáil has agreed a €1.3 million spending limit for candidates in the presidential election, if there is one.
The Taoiseach, Mr Ahern, insisted the order was a "purely precautionary" measure required under legislation.
"I do not have any news" about the possibility of an election, he told the Fine Gael leader, Mr Enda Kenny.
The Opposition expressed concern about the measure, listed as a motion for approval under the Electoral Act 1997 and the Presidential Election (Reimbursement of Expenses) Regulations.
Mr Kenny quoted the explanation that stated the presidential election, if held, would take place in October and the election period would commence before the Dáil and Seanad resumed in the autumn, so approval was needed now.
Mr Kenny asked: "Has the Taoiseach had any indication that it might be necessary to have candidates nominated for the presidential election or does he intend to nominate a candidate? In other words, do you have any news?"
The Labour leader, Mr Pat Rabbitte, said it was proposed to pass the measure "on the nod" and this was "less than respectful". The Taoiseach was "permitting a spend of €1.3 million and, quite frankly, that is anti-democratic. No party other than the Taoiseach's can afford anything like that," Mr Rabbitte said.
Mr Ahern said he did not believe that anyone would spend anything like that, but it was included because it was in the law already passed and the figure had to be fixed.
