The Fiscal Advisory Council has said extra spending increases in this year's Budget would not be advisable, as it would run the risk of breaching spending rules.
In a pre-Budget Statement, the Fiscal Council says there will be a near-doubling of public capital investment over the next four years, which will move Ireland back to among the very highest levels of capital spending in the EU - whilst still complying with all fiscal rules.
The council says the economy is doing extremely well - but that is not a reason to cut loose with extra, unplanned spending.
It says capital spending will almost double over the next four years to reach one of the highest levels in the EU as a share of Government revenue.
It says the Government can do that whilst still respecting the fiscal rules, reducing Government debt and running a balanced budget.
But it would like the Government to publish a detailed account of how the proposed new rainy day fund will work - especially how it can be used to help the economy in a downturn.
It sees Brexit as the biggest danger to the economy in the medium-term, and says sticking to all aspects of the fiscal framework is the best way to Brexit-proof the public finances, and prevent forced cuts to public spending.