"There is a hard core group of countries that are blocking," said an EU diplomat, on condition of anonymity, after informal talks between the bloc's justice and interior ministers in the southern Finish city of Tampere.

The issue of national vetoes on cross-border police cooperation in criminal affairs has festered into a major obstacle to the European Union's security ambitions.

While only around four of the 25 EU countries were against a move from unanimity decision-making to qualified majority voting to decide such matters, only three member states appeared to be fully in favor, diplomatic sources said.

Those states that diplomats most often named as being against the move included Germany, the Czech Republic, Ireland and Malta, while France, Luxembourg and Spain were cited as most ready to take the leap.

Some countries fear that a change to majority voting would surrender control over or water down national security legislation. Others are concerned that it may conflict with their constitutions.

Urgent need for change

Yet many countries agree there is urgent need for change, given the terror attacks in London and Madrid and three foiled plots in Europe this year, to ensure that draft legislation does not gather dust as it awaits unanimous endorsement.

Three years elapsed before a compromise was reached on a warrant easing the exchange of evidence between EU countries. Other projects have remained on hold for almost as long, including accords on common minimum rights for suspects, cross-border investigations and protecting information used for security purposes.

"The fact that practical results are insufficient undermines the EU's credibility at EU level both among citizens and civil servants," said Finnish Interior Minister Kari Rajamaki, co-hosting the talks as EU president.

"What citizens expect of the EU is added value in security matters, especially in combating organized crime and terrorism," he said.

At a press conference after the talks, he and EU Justice Commissioner Franco Frattini refused to name the countries that were blocking, with Rajamaki saying only that the results of the talks would now be analyzed.

Germany prefers reviving EU constitution

Many issues would have been resolved by the planned EU constitution, which was rejected by French and Dutch voters in May last year and fell into limbo as countries gave up ratifying it.

In an effort to keep up with fast-evolving security needs, the European Commission -- the EU's executive body -- has urged members to use an article from a past treaty to move to so-called qualified majority voting.

Unfortunately for those in favor of change, shifting to qualified majority voting -- a system in which 62 percent of Europe's population must be represented -- itself requires a unanimous decision.

"The question is whether we can accept to take decisions that may be against our own interests," said Bavarian Interior Minister Günther Beckstein, representing Germany's states at the talks, before Friday's meeting.

"I'm convinced that Europe has not come far enough yet for us to arrive at any sort of majority decision now," he said.

Germany argues that adopting such a system would undermine attempts to revive the constitution, which Berlin has a mandate to take forward during its EU presidency, which starts in January.

Despite the fingers pointed in her direction, German Justice Minister Brigitte Zypries said: "No one can say that Germany is blocking," as 14 of the countries whose ministers spoke expressed doubts about abandoning unanimity.