The German Chancellor, Angela Merkel, has suggested negotiations on a new treaty to replace the now failed EU Constitution could go ahead without Poland.
In a raising of the stakes at the Summit of EU leaders in Brussels, the German Presidency is to take a vote on the issue following Poland's refusal to accept a number of compromises on the most contentious issues.
Earlier, the Minister for Foreign Affairs, Dermot Ahern, said he is hopeful that agreement on the treaty can still be reached.
He said that although there are differences between the failed constitution and the new proposed treaty, the core principals are retained.
There is still no agreement to one of the key issues - Poland's objection to proposed changes in the voting system.
Speaking to Polish television this evening, the country's Prime Minister Jaroslaw Kaczynski has warned a compromise may not be possible.
Supporters of the treaty argue that reform of the complex EU decision-making structures is needed for further enlargement, and to tackle challenges such as climate change and globalisation.
They say it will provide clear leadership, a stronger voice for the EU in the world and more say for European and national parliaments. Critics fear a dilution of national sovereignty.
Britain has said it does not want to be legally bound by a Charter of Fundamental Rights, which includes a broadly defined right to strike. It also wants to shrink the powers of a proposed EU foreign minister, seeks an opt-out from EU justice cooperation and opposes obligatory social security payments to migrants.
18 EU nations ratified the former draft, the so-called Constitution, but even they accept it must be cut to allow France, the Netherlands and Britain to avoid referenda their governments might lose.
Some key institutional changes provided for in the Constitution will be kept, such as creating a president of the European Council of governments elected for 2-1/2 years instead of the current six-month rotating presidency which has grown unwieldy in the enlarged EU.
