The Fianna Fáil leader's calling on the Taoiseach to clarify when the general election will be held.
Micheál Martin's comments come ahead of an interview by Enda Kenny on RTE's The Week in Politics this afternoon.
For over a week now, Mr Kenny's refused to quell speculation that an early poll would be held next month.
Mr Martin says this isn't acceptable:
Meanwhile, the Fianna Fáil leader's accused the coalition of "bribery" in advance of the election.
His comments come after it emerged the coalition plans to spend as much as 1.5 billion in bailouts to Departments such as Health to make up shortfalls in funding before the year end.
That's on top of extra money for spending next year and tax cuts to be announced in Tuesday's budget.