The European Parliament said on Wednesday it will refuse any concessions to satisfy Hungary or Poland, that are blocking a €1.8-trillionEU budget and stimulus package because it ties funding to respect for the rule of law.

"No further concession will be made on our side," the parliament said in a statement following a meeting of the political group leaders.

Ahead of an EU leaders summit on Thursday, they urged member states "to adopt the package and launch the ratification process as soon as possible." 

Poland, Hungary dig in 

Earlier, Poland and Hungary toughened their rhetoric against the EU. 

Polish Prime Minister Mateusz Morawiecki said a "European oligarchy" was trying to bully weaker EU members, while his Hungarian counterpart Viktor Orban called the conditionality plan a form of "blackmail" against member states opposed to immigration.

"This is a turning point in EU history. Making decisions based on the arbitrary provisions of regulation may lead to its collapse- Polish PM

Speaking in Warsaw, Morawiecki struck a defiant tone and warned that imposing new conditions for funding could lead eventually "to a break-up of the EU".

"This is a turning point in EU history. Making decisions based on the arbitrary provisions of regulation may lead to its collapse," he said.

Morawiecki's nationalist government has pushed through a string of controversial judicial reforms that have put Poland on a collision course with the EU over concerns the changes undermine the rule of law.

In Hungary, Prime Minister Viktor Orban has been implacably opposed to schemes to resettle refugees arriving in other parts of the continent, notably Italy and Greece.

Slovenian Prime Minister Janez Jansa, a close ally of Orban on migration, weighed into the row on Wednesday, saying EU institutions should "not be involved in member states' internal political conflicts".

But other Central and East European states including Czech Republic, Romania and Slovakia opposed the vetoes.

Possible compromise? 

Orban said in a statement that Hungary had used its veto because it saw the rule of law conditions as tantamount to "blackmailing" countries that oppose migration.

"In Brussels today, they only view countries which let migrants in as those governed by the rule of law," Orban said.

"In our view, tying economic and financial questions to political debates would be a grave mistake, one that would undermine Europe's unity," he said.

But Orban also hinted at a possible compromise offer, saying that a deal should contain a clear definition of rule of law and a mechanism for countries to appeal sanctions.

"Without objective criteria and possibility of legal remedy, no procedure that aims to penalise member states should be based on it," he said.

'Europe cannot be held hostage' 

The vetoes have triggered outrage in Brussels, with senior European diplomats saying there was no question of the other countries agreeing to loosen the rule of law condition.

France's Europe Minister Clement Beaune said the EU was looking at "practical solutions" for resolving the impasse.

"We are looking, as a last resort, at how to proceed without the countries that are blocking" a deal, he said.

Beaune said EU officials would consider "clarifications" to the rule-of-law requirement, "but certainly not by calling it into question, because our values and our European project are at stake."

"Europe cannot be held hostage by a certain number of governments that do not want to move forward, that do not respect the bedrock of our political project," he warned.