Home Secretary Theresa May is under pressure to explain what measures the Government is taking to manage the risk posed by a series of terror suspects when existing controls expire during the course of this month.
Labour said court papers showed that orders - known as terrorism prevention and investigation measures (Tpims) - on around six suspects were on the point of being lifted.
They include one suspect who MI5 assessed could rapidly gain access to firearms, with a "real risk" that he would try to revive plans to mount a terrorist attack in the UK if he was not subjected to a Tpim.
Three others were said to be prepared to travel abroad in order to engage in terrorist-related activity while a judge found there was "every reason" to believe that a fifth would have killed himself along with a large number of other people if the airline bomb plot had not been foiled in 2006.
Shadow home secretary Yvette Cooper, who is staging an opposition day debate in the Commons to press ministers on their plans, said the Government needed to explain what steps it was taking to protect the public.
"Theresa May can't hide away on this. Her decision to weaken terror controls means terror suspects described by the courts as highly dangerous only a year ago will now face no restrictions on London streets," Ms Cooper said.
"Does she believe these men are no longer dangerous? Or is she increasing the security risk? We need to know."
Tpims, which were introduced in January 2012 by the coalition Government to replace the more restrictive control orders brought in under Labour, have a maximum time limit of two years.
They are imposed by the Home Secretary, who is given access to secret evidence which cannot be placed before a jury, and can include restrictions on travel, overnight residence and finance.
Labour said that an analysis of court documents showed that among the suspects whose orders are set to expire are:
Suspect CD. Court papers are said to show MI5 assessed there was a "real risk" he would seek to revive his plans to undertake attacks in the UK or engage in other terrorism-related activity if he was not subject to a Tpim. He was said to be able to "quickly and covertly" purchase firearms if he had the necessary money, and that he had a number of criminal associates in London.
Suspect CE. Court papers are said to show MI5 assessed he was part of an extremist network whose members have used false documents in order to try to reach to Somalia to engage in terrorist training. It was argued in court that controls were needed to restrict his ability to travel to Somalia to meet associates in order to engage in terrorist-related activity in the UK.
Suspect AM. A judge was said to have concluded that if it had not been for the disruption of the airline bomb plot, "there is every reason to believe that AM would have killed himself and a large number of other people". The judge found there would need to be "convincing evidence of a change of heart" to justify lifting controls.
Suspect CF. Court papers are said to show he has a record of absconding while electronically tagged on bail. He was said to have used a false Portuguese passport to leave the country, giving rise to an assessment he may have been assisted by an extremist network.
Security Minister James Brokenshire has said the police and MI5 had "tailored plans" to manage the the risks posed by the suspects once the Tpims are lifted.
Ms Cooper said: " Theresa May deliberately changed the rules so that restrictions have to be stopped this month no matter how great she and the courts believe the risk might be.
"Theresa May needs to tell us urgently. Does she believe these men whose restrictions she is lifting now are no longer dangerous? Does she think it is now safe to let them go without restrictions?"