The acting chair of the Irish Fiscal Advisory Council has said the debt ratio here will be 'almost at historic highs' after the coronavirus crisis.
Sebastian Barnes told Newstalk Breakfast: "The bad news is that the economy, even after the lockdown measures have passed, is going to be very weak - and that's why we're going to need these big stimulus measures to help get the economy back and to help get unemployment down.
"So that's going to be a difficult phase in itself.
"Once that's completed - and it's very uncertain, perhaps we're looking two or three years down the line - but certainly within the five years of a government I think, they are going to have to face some quite difficult decisions.
"We've done a lot of different scenarios and calculations - and our sense is that fiscal adjustment will be required, the debt ratio will be very high - almost at historic highs - and there will be a big deficit, perhaps around 3% still by 2025.
"But the good news is that even in quite a severe scenario where quite a lot of things would go wrong over the next few years, the amount of adjustment that would be needed is far less than was required after the financial crisis.
"And that also means it can be done more gradually, maybe in a more considered way - and against the background of an economy that's going to be in kind of good shape, whilst last time it was done at a time when the economy was contracting very sharply".
The Fiscal Council's latest report suggests government debt could return to near-record levels - ranging from 114% to 160% in 2021, up from 99% in 2019.
It says the high debt level will leave the economy more vulnerable to future shocks.
It adds that it could take two to 3.5 years to return to pre-crisis levels of activity.
But by contrast, the Irish economy took 11 years to recover after the financial crisis.
Mr Barnes said cuts of up to €15bn are in a worst-case scenario: "I think, particularly if interest rates stay low, it could be phased over a number if years.
"It doesn't have to be put in dramatically - and if you look at the sorts of measures that would be required, some of it could be achieved perhaps through restraint or freezes on say pay, or it could be some tax measures.
"But things that aren't dramatic I think, while last time the measures that were taken were really extremely sharp."
He said one difference is public investment should not be cut dramatically.
"For the stimulus it would be good to focus on public investment - that can often be very rich in jobs and also of course it yields a long-term benefit by having investment during that phase.
"And it may be a good idea within that to bring forward some projects so they can really get ready and get moving very quickly to get the economy moving."
He said difficult choices would have to made in the medium-term on prioritisation.
"I think on the investment side there may well be scope to re-proritise , and of course that will have to be dependent a little bit on how things evolve in the coming years".
One example he said is housing: "It may be that as demand re-balances there's actually an opportunity to accelerate that kind of spending".
