Home Secretary John Reid is to make a fresh attempt to extend the maximum period that terror suspects can be detained without charge beyond 28 days.
Mr Reid told ministers at Thursday's Cabinet meeting he would attempt to find cross party consensus on a longer detention period for questioning, said Prime Minister Tony Blair's official spokesman.
Following consultations with the police, Mr Reid said police chiefs thought it was "right and proper" for the Government to address the issue once more, following a failed attempt to introduce 90-day detention in 2005.
Mr Reid told the Cabinet that since changes extending the maximum detention period from 14 to 28 days were introduced there had not yet been a case in which a longer period of questioning was needed.
But he said detectives investigating last year's alleged plot to carry out terror attacks on airliners had required the full four weeks to complete their investigations and there were fears that future cases may need longer still.
Mr Blair's spokesman told a regular daily press briefing following Cabinet: "The Home Secretary... said he has been discussing the issue of the limits on pre-charge detention in terrorism cases with leaders of the police service and others.
"The police service has now concluded that it is right and proper for Government to address this issue and wanted the Home Secretary to discuss it with colleagues in Government and more widely, with a view to seeing whether a consensus can be achieved.
"The Home Secretary raised this issue with colleagues this morning and the Cabinet has agreed to try to establish a national consensus on this.
"The Home Secretary outlined that, although it had not yet been the case that 28 days had been inadequate, all 28 days were needed for the August airline case and it was quite possible to envisage circumstances where the police may need more than 28 days, because the scale of the terrorist threat is becoming larger and more complex, because the scale of operations is increasing and the amount of evidence is growing larger.
"The sequential nature of the investigation could mean charging decisions taking longer than 28 days."
