Jacqui Smith suffered a devastating double blow to proposed new laws allowing terrorist suspects to be detained for up to 42 days without charge as the plans were savaged in two highly critical reports.
The damning verdict came from two all-party committees, which declared that there was no evidence for extending the current time limit of 28 days.
Peers and MPs on the respected Joint Committee on Human Rights warned that ministers had failed to make a case for extending the limit, while the all-party Commons Home Affairs Committee warned that detention could be seen as "internment" by Muslims.
The Human Rights committee said evidence the Crown Prosecution Service had "managed comfortably" under the current limit was "devastating" to the Government's argument.
It said: "Any extension to pre-charge detention is a serious interference with liberty that requires a compelling, evidence-based demonstrable case. We do not accept that the Government has made out a case for extending pre-charge detention beyond the current limit of 28 days."
It said plans to allow Parliament to debate extensions to the limit would produce a "serious risk of prejudice" to any future trial.
Andrew Dismore, the committee chairman, said: "All of the evidence we and many others have gathered points one way. The public can be adequately protected by a combination of the alternatives we have advocated." The Labour-dominated Home Affairs Select Committee acknowledged Britain faced a "real and acute" terrorist threat, but also concluded that ministers and police had failed to make a convincing case for going beyond 28 days.
It said: "We consider there should be clearer evidence of need before civil liberties are further eroded."
They reached their conclusion after a majority of witnesses to the committee, including the Director of Public Prosecutions, opposed any increase.
The MPs suggested the Civil Contingencies Act could be used instead for emergency detention for more than 28 days in exceptional circumstances.
They also warned that Muslims could view an increased detention period as a form of internment.
Calling for alternatives to longer pre-charge detention to be used to secure convictions, the MPs denounced the ban on the use of intercept evidence in terrorist prosecutions as "ridiculous".
Kate Allen, UK director of Amnesty International, said: "The consensus against extending pre-charge detention limits is growing day by day."Reuse content