Minister for Housing Eoghan Murphy said he is "concerned" that the help-to-buy scheme could be inflationary.
Speaking on RTÉ's The Week In Politics, Mr Murphy said he was worried that the first-time buyers' grant "hasn't achieved the delivery on the [housing] supply side that we need".
A review is under way to see if the scheme is pushing up house prices, he said, adding that he will make a decision on it when the review is completed.
The scheme provides first-time buyers with a rebate of income tax of up to 5% of the purchase price of a new home, up to a value of €400,000.
The maximum tax rebate available to first-time buyers is €20,000.
Sinn Féin’s finance spokesperson Pearse Doherty has welcomed a newspaper report that the help-to-buy scheme is to be axed in the upcoming budget.
The Sunday Times reported that the Government is preparing to scrap the scheme.
Citing a government source, the Sunday Times said: "Help-to-buy was an attempt at increasing supply by increasing demand, but the Department of Finance review now under way will almost certainly find it has been inflationary."
"It is really disappointing that the Government didn't heed the warnings from Sinn Féin and others that the help-to-buy scheme would only serve to drive up house prices," said Pearse Doherty.
"While I welcome reports suggesting that this scheme is to be axed in the upcoming budget the reality is that the damage has already been done and can be seen in the dramatic increase in house prices.
"What we need to see now is a real effort to tackle the supply and affordability issues. That must be led by major investment in building social housing," added- Mr Doherty.
Meanwhile, Mr Murphy has refused to back the former minister's commitment that all homeless families in Dublin will be moved out of hotel accommodation by 1 July.
Last month, then housing minister Simon Coveney reiterated his confidence that the target would be reached.
However, speaking on RTÉ's The Week In Politics, Minister Murphy said: "I've demanded a meeting with the heads of the four [Dublin] Local Authorities early this week to see exactly where we are with those numbers.
"Once I've had that meeting, I will be able to tell people exactly what's going to happen."
Pressed by Fianna Fáil's Dara Calleary if the July deadline was moveable, Mr Murphy replied: "It was an ambitious target."