Charles Clarke has been forced to apologise for a "shocking" Home Office blunder that allowed more than 1,000 foreign prisoners - including murderers, rapists and paedophiles - to escape possible deportation after their release.
Officials are still trying to track down at least 900 of them, admitting that some of the missing criminals could be violent offenders.
The Home Secretary shrugged off suggestions he should resign over the failure, which the Government blamed on a "communication breakdown" between prison chiefs and immigration officers.
The fiasco - which only came to light after repeated questions from a Tory MP - plunged Mr Clarke into the worst crisis of his 16-month spell in charge of the department and dismayed Labour chiefs hoping to highlight the party's law and order credentials in next week's local elections. The pressure on him intensified last night when it emerged that 288 of the prisoners were freed after August 2005 when MPs first alerted the Home Office to the problem.
The crisis began when Mr Clarke disclosed that 1,023 foreign national prisoners had been released in the past seven years without any consideration of whether they should be deported. They included three murderers, nine rapists, five paedophiles, 34 other sex attackers and 93 robbers, as well as 41 burglars, 20 drug smugglers and 54 convicted of assault.
The vast majority were serving sentences of at least 12 months, and in 160 cases the courts had recommended deportation.
The releases occurred between February 1999 and last month, covering time in which Jack Straw, David Blunkett and Mr Clarke have been Home Secretary.
Mr Clarke acknowledged that only 107 of the former prisoners had been located and questioned, with 20 of them being deported. Officials were unable to say how many of the offenders were serving life sentences or whether any had reoffended after their release.
The Home Secretary said he took responsibility for a "shocking state of affairs". But he added: "I do not think it is a resigning matter."
Asked on BBC Radio Five Live last night if he believed all 1,023 prisoners would be detained for possible deportation, Mr Clarke said: "I can't say hand-on-heart that we will identify where each one of those is."
Opposition parties stopped short of calling for his resignation, but Sir Menzies Campbell, the Liberal Democrat leader, said his position was "pretty fragile". "All the Government's tough talk on crime counts for nothing in the face of this incompetence," he said.
David Davis, the shadow Home Secretary, said: "This astonishing admission by the Home Office is the latest in a long line of failures which have jeopardised the protection of the public."
Richard Bacon, a Tory member of the Home Affairs Select Committee whose questions led to the revelation, said: "This appears to illustrate a kind of administrative chaos that is hard to credit."
Mr Clarke is expected to be forced to make a parliamentary statement today after Michael Martin, the Commons Speaker, signalled his irritation that the news had been released to journalists rather than MPs.
The 1,023 foreigners slipped through the net as numbers of overseas nationals in UK jails soared to more than 10,000. They were not identified by prison staff before their release.
Under Home Office rules, prisoners from outside the European Economic Area are supposed to be considered for deportation if they are sentenced to at least one year in a UK prison.Reuse content