Taoiseach Leo Varadkar has said EU budget plans risked making Ireland pay more and receive less from Brussels.
Mr Varadkar joined EU colleagues early yesterday morning, after a long and fruitless day at Leinster House, for talks aimed at framing EU spending plans for the seven years from 2021 to 2027.
But compromises could not be found between the big payers into Brussels' coffers and the developing states of the former Eastern Bloc, so the leaders' summit was cut short with a new meeting now likely next month.
The new summit chairman, former Belgian prime minister Charles Michel, ended a second day of haggling over the EU's €1.1trn budget blueprint.
The stand-off between big contributors, known as the "frugals", and big-spenders, known as the "cohesion group", could not be bridged.
This tussle over EU funding is a Brussels ritual which happens every seven years. But this time it was intensified by the need to bridge a €12bn per year net gap left by the departure of the UK, and new spending demands for climate change, migration and defence co-operation, which will reduce farming, regional and social spending.
Speaking during a break on day two of the EU summit in Brussels, Mr Varadkar said he had made Ireland's position clear during a meeting with Mr Michel and European Commission President Ursula von der Leyen, after 2am yesterday morning.
"The proposal on the table is one we can't accept. Essentially it means Ireland will contribute much more to the EU budget but we'll actually receive less back in terms of payments to Irish farmers and also funds for regional development and social development," the caretaker Taoiseach told reporters during a break in discussions.
Brussels officials signalled Ireland's big worry was the loss of €78m a year in farm funding. But they accepted that Ireland had also long ago made it clear it is prepared to pay in more than the net yearly contribution of approximately €200m.
"We accept that as a country which has a growing economy and a country that has full employment that we will have to pay more into the European budget over the next seven years.
"But what we can't accept is that we will pay more in but we would see very significant cuts to CAP and to cohesions funds," the Taoiseach added.
Mr Varadkar told the 'Farming Independent' on Tuesday that Ireland wanted to keep farm spending at current levels.
But under these proposals the Common Agriculture Policy would see a cut of up to €53bn over the coming seven years - with Ireland's estimated hit put at €78m a year.
Earlier, Danish Prime Minister Mette Frederiksen struck a particularly downbeat note over the prospects of a budget compromise.
Denmark is one of the self-styled "frugal" four nations - along with the Netherlands, Sweden and Austria - opposed to Mr Michel's proposals.
They insist Mr Michel's €1.1trn budget plan is excessive and must be cut back.
They are also calling for the EU budget process to be modernised.
Leaders are at odds over how much to increase the long-term budget - called the multi-annual financial framework (MFF).
They also disagree over how spending should be shifted between priorities, and how much each member should pay as a percentage of its gross domestic product (GDP).
Against the "frugals" are France, which like Ireland wants farm payments protected, and more money for European defence projects.
Cutbacks are also opposed by the so-called "friends of cohesion", a group of eastern and southern countries seeking to ring-fence their grant money.
Dutch Prime Minister Mark Rutte came to the summit armed with just a small apple and a biography of the Polish composer Frederic Chopin, to while away the hours while summit chairman Mr Michel did the rounds of the other government leaders trying to shift their entrenched demands. But Mr Michel failed in his efforts.
EU leaders made no headway on Thursday in fractious talks on a joint 2021-27 budget that was left with a 75 billion euro ($81 billion) hole after Britain's departure at a time when they face costly new challenges from climate change to migration.