European Union home affairs ministers have promised that in October they will agree on a set of Europe-wide rules requiring companies to store phone call and email data.
The pledge was made at an emergency meeting of ministers in Brussels on Wednesday in response to the bombings in London last week which killed over 50 people.
The data rules, which have been under discussion by ministers since April last year, are highly controversial because of fears that they would infringe data privacy rules and impose excessive costs on industry.
Privacy or life?
But France's interior minister Nicolas Sarkozy on Wednesday dismissed objections that the cost of the rules would be too high: "What would cost us dear would be to have innocent victims," he said. He said that telephone records had played an important part in identifying and arresting terrorist suspects in the UK, France, Spain and Germany.
The commitment to agree on the rules in October came as part of a wide-ranging package of measures which EU ministers want to decide as soon as possible in their efforts to increase European cooperation in the fight against terrorism.
"There is a determination on the part of all countries that we cannot delay in getting this right," said Charles Clarke, UK Home Secretary, who was chairing the meeting.
What it means
The rules will require fixed and mobile telephone operators, ISPs (Internet service providers) and SMS (short messaging service) providers to keep data for at least a year with a possible maximum of three years. Only traffic data such as the time, duration and destination of calls would be kept, not the content of communications.
Law enforcement agencies in any of the EU's 25 member states would be able to consult the records under the "principle of availability".
Rights, liberties and security balance sought
To address concerns about infringements of personal privacy, the European Commission, which proposes draft legislation, said it would present rules on data protection in September to accompany the rules on data retention. EU Justice Commissioner Franco Frattini said it was important to "keep a balanced approach between fundamental rights and liberties and security."
However, members of the European Parliament, have warned that the rules are unnecessary and that police and intelligence services would obtain the data they needed though other means, without the risk that people's civil rights could be infringed.
UK Liberal Democrat MEP Sarah Ludford, said that the "investigation of the London as well as the Madrid bombings could be done on the basis of records already kept for several months for billing purposes, with targeted 'freezing orders' for suspects' communications."
At Wednesday's meeting, ministers also pledged to agree on a range of additional measures designed to help in the fight against terrorism including a promise to speed up the introduction of biometrics (including facial recognition and digital fingerprint storage) in visas.