Shadow home secretary Yvette Cooper has called for answers into how 27-year-old Mohammed Ahmed Mohammed was able to evade surveillance and breach a court order.
Somalia-born Mohammed, who was subject to a Terrorism Prevention and Investigation Measures notice (Tpim), managed to escape after changing into a burqa on a visit to a mosque.
Describing the situation as "extremely serious", Ms Cooper said: "Clearly police and security agencies will be doing everything possible to locate this terror suspect and ensure public safety.
"The Home Secretary also needs to provide information about the decisions made over Mohammed Ahmed Mohamed's Tpim, how he was able to abscond and what the risks to the public are."
Cooper said the 27-year-old is now the second terror suspect to breach a Tpim in London in the space of ten months, after Ibrahim Magag absconded in a black cab last Christmas.
The Shadow home secretary said given the "long-standing concerns over the replacement of control orders and the limitations of Tpims", there should be an independent review into the adequacy of the terror control measures.