Fine Gael is proposing new legislation to asses opposing parties' spending plans.
The Private Members Bill would allow the Irish Fiscal Advisory Council to inspect parties spending ahead of each budget.
Deputy Martin Heydon believes Fianna Fáil's money demands need to be examined.
"Either Fianna Fáil are promising way more than they could actually deliver if they were in government or they would have to increase taxes significantly to meet all the promises they're making," he said.
"I think we need the likes of the Fiscal Advisory Council to analyse and call out opposition who go around promising everything to everybody without saying how they would raise that additional revenue."
He added: "I think the public need to be able to make up their own minds about all the commitments and plans that are there. Government and Fine Gael work within very tight parameters that have been set down.
"If the opposition are going to call for a significant increase in expenditure, the public deserve to know how Fianna Fáil would plan to pay for that."