EU leaders heard out Hungary's Viktor Orban and Poland's Mateusz Morawiecki on Thursday as they defended their shock veto of the EU budget and coronavirus recovery plan, which has plunged the bloc into a new crisis threatening joint efforts to fight the epidemic.

The bloc's 27 heads of state and government spent fewer than 15 minutes on the issue at the start of a video summit, with German Chancellor Angela Merkel, who holds the EU's rotating presidency, responding to the rebels on their behalf.

Warsaw and Budapest, with the support of Slovenia, threw the EU into turmoil this week by using their veto to bloc the EU's combined 1.8-trillion-euro ($2.1 trillion) post-virus recovery plan and long-term budget.

While not a complete surprise, the stand-off angered EU partners, with many keenly awaiting payouts from the stimulus to help fix economies shattered by the pandemic, and with worse feared to come.

But an EU official said EU Council President Charles Michel, who hosts European summits, made sure ahead of time that the conversation would remain short and "under control" to allow for later mediation.

"The three naysayers reiterated their reasons for their opposition, without any fresh or new nuance," another senior EU source told reporters.

The nationalist governments are furious at their EU partners for backing a decision that ties the disbursement of bloc funds to the respect for the rule of law and European values.

- 'Men of trouble' -

Morawiecki and especially Orban are frequent scourges of EU policy, with anti-EU rhetoric rife in both their governments despite Hungary and Poland being the biggest receivers of EU spending.

"Hungary and Poland stated what they didn't want, not what they did -- true to their form as men of trouble, not of solutions," said an irritated European diplomat.

The plan to tie EU funds to the rule of law, strongly defended by the European Parliament and mainly northern member states, has the votes to be approved by a qualified majority of members.

But Hungary and Poland are fighting back by using their veto against allowing the EU to raise funds to finance its 750-billion-euro recovery plan and against the trillion-euro 2021-2027 budget, which require unanimity.

"Where does it stop?" Poland's Morawiecki demanded of his EU counterparts, according to a source with knowledge of the proceedings.

"You are using this only against us and circumventing the treaty," Morawiecki reportedly said. Before the summit he had slammed an alleged "European oligarchy" that was trying to bully weaker EU members.

The rule-of law issue is hugely sensitive for both countries. Poland is already under an EU investigative procedure over its efforts to trim the independence of the judiciary, as is Hungary for an erosion of democratic norms, such as press freedom, under Orban's rule.

- 'On the table' -

The rest of the bloc had hoped that the matter had been settled in July after a four-day and night summit hammered out an apparent budget compromise.

"Blocking the adoption of a decision on the recovery plan negatively affects the whole EU, including the citizens of Hungary and Poland," Romanian Prime Minister Ludovic Orban -- no relation to Viktor Orban -- told AFP.

Germany, which holds the EU presidency until December 31, will work furiously behind the scenes to defuse the row, and some diplomats think Orban and Morawiecki could be persuaded quietly to accept guarantees of fair treatment.

"There was nothing to discuss at this political level, it's too early. They want the discussions happening at a lower level," said analyst Eric Maurice, of the Schuman foundation.

France and the Netherlands have invoked the possibility, seen as implausible by many, of by-passing the log-jam by pushing ahead with an intergovernmental recovery plan, without the holdouts.

In Brussels, a senior European source warned this would be premature and technically complex but confirmed it was "on the table".

The summit was originally planned to delve into the pandemic and to coordinate a strategy to prevent a third wave next year.

Leaders were also expected to take the temperature of post-Brexit trade talks, with time fast running out to strike a deal with Britain before it leaves the single market on January 1.

The video summit was for a time seen as an unofficial deadline for those talks, but the negotiations look set to stretch to next week.