The Yorkshire Post can reveal that almost 1,000 terror suspects have been held without trial since 2001 under the previous 14-day limit.
But while Prime Minister Tony Blair argued for dramatically raising that limit, no one in Government was checkin
g for how many days all these detainees were being held.
Critics rounded on the Home Office's admission last night, calling the inability to prove how many police investigations actually were pushing the 14-day limit "inexcusable" and claiming it showed calls for 90 days were based on an "unsubstantiated hunch".
A compromise of 28 days was introduced in July after Mr Blair's 90-day plan was defeated in the Commons last November, but he and Home Secretary John Reid are poised to launch a fresh attempt to get it on the statute book following the alleged airline bomb plot over the summer.
The task will be made harder, however, since revelations from Home Office Minister Tony McNulty to Parliamentary questions.
Mr McNulty said 997 suspects were detained from September 2001 to March under the 2000 Terrorism Act, but added: "The Home Office does not collate information on the length of time an individual is detained prior to being charged or released."
Shadow Home Secretary David Davis, the Haltemprice and Howden MP, said last night that terror laws are "very sensitive and must be deployed appropriately so as to retain community confidence in them".
But he added: "These statistics suggest that is not the case.
"It is inexcusable the Government doesn't know the basic facts about detention without charge when it has already asked Parliament to double the time limit and looks set to press for a much bigger extension."
Liberal Democrat home affairs spokesman Nick Clegg called the lack of evidence "breathtaking".
"If there remained any nagging doubt about the feebleness of taking such a leap into the dark, this ends it," said the Sheffield Hallam MP.
"It's simply mind-boggling that they propose such massive restrictions on liberty on the basis of nothing more than an unsubstantiated hunch. If they have no statistics, I can't see how they can rebuild their case.
"It confirms my view that so much of what they're doing on terror is about capturing headlines and little else."
Underlining Mr McNulty's comments, a Home Office spokesman said last night: "We don't collect figures for every single thing. That's one of the things we don't keep records of.
"It doesn't mean police don't hold them, it just means we don't hold them centrally."
Mr McNulty's statement was prised out with an official question from Conservative backbench MP Shilesh Vara, who asked for a range of terror statistics since 2001, including on which day of their detention former suspects had been released or charged.
In addition to admitting the Home Office had little grasp of the 997 cases, Mr McNulty revealed that 154 suspects were charged under specific terror offences while more, 175, were charged under existing legislation.
Mr Vara said: "It's extraordinary that the Government hasn't done the most basic research on what is supposed to be a centrepiece of their next legislative agenda.
"If ever there was an
example of soundbite politics glossing over reality this
is it."
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