Taoiseach Enda Kenny has arrived for more talks with his fellow European leaders after a long night around the negotiating table.
Britain's prime minister David Cameron has said he will do 'everything he can' to secure a deal on his proposed EU reforms.
But there have been ultimatums from France and Belgium, who have warned Mr Cameron that if Britain votes to leave, there is no going back.
Greece has also threatened to veto Mr Cameron's deal - over the handling of the migration crisis
But Estonia's prime minister Taavi Roivas is confident an agreement can be reached.
“I do believe that it is possible to reach a fair deal today, I understand that of course we all pursue our national interests, but we should also bear in mind that should Britain leave, we all get nothing.”