After a rare public debate on a thorny issue, first put up for discussion in 2003, the EU's German presidency found that no agreement could be reached, with six countries, including Britain, opposed and a unanimous endorsement needed.

"We simply have to note that, at the moment, we cannot adopt this," German Justice Minister Brigitte Zypries, whose country holds the EU's rotating presidency, told her European counterparts at a meeting in Luxembourg on Wednesday.

"I think it will be simpler, perhaps, to start up the discussion again once we've had the (EU) summit and once we know what is going to happen regarding the decision-making structure," she said.

Minimum EU standards needed

Indeed the issue goes to the heart of debate about the EU's future reforms, the topic that will dominate the June 21-22 summit, and proves how difficult it is for the bloc to function since growing to 27 members.

This measure would set minimum EU standards on rights like access to a lawyer, for free if needed, an interpreter and documents translated in their native tongue, as well as information about their entitlements.

It brings little more than the guarantees for suspects laid down in the European Convention for the Protection of Human Rights and Fundamental Freedoms, yet the EU was unable to agree. The issue was not one of substance but of process.

"Once again, we seem to be failing to meet one of the most important political challenges," EU Justice Commissioner Franco Frattini warned. "We've often said that we've got all these law enforcement measures, we should balance them with greater freedoms. We keep saying it, but we never do it," he told the ministers.

Opening a Pandora's box

But Britain, Cyprus, the Czech Republic, Ireland, Malta and Slovakia demanded that the planned legislation be limited to cross-border cases or those that fall under the scope of the European arrest warrant system.

They generally argue that the EU should add value in terms of legislation and rights and not impose procedures on the domestic criminal systems of the member countries.

"The proposal on the table from the presidency on which we are asked to pronounce isn't one we could agree to," said British Ambassador John Grant. He expressed concern about "whether it is appropriate for the European Union to legislate in respect of domestic cases."

"It's a question of principle," Ireland's representative said, while Malta's minister said the measures would "open up a Pandora's box."

Britain wants to retain unanimity voting on justice issues, particularly police matters, rather than move to more qualified majority voting, which would have happened had the constitution been accepted.

But the EU charter was rejected by French and Dutch voters in referendums two years ago, meaning it is technically a dead letter, and Britain has been staunchly defending its stance in the run up to the summit in Brussels.

If only the constitution were in place

The leaders aim to thrash out the main pillars of an alternative treaty of reforms, to be polished up at an intergovernmental conference, perhaps in July, and ratified before European Parliament elections in 2009.

Zypries said the rights problem would not have arisen if the constitution, most of which Germany wants to keep, had been in place, but she insisted that the public debate she organized was not timed to coincide with the summit.

"I think it is fair that the European public should know who is preventing added value being brought to European citizens," she said.