The Home Office is considering banning terror suspects from visiting controversial mosques, Sky sources say.
Suspects subject to Terrorism Prevention and Investigation Measures (Tpims) would not be allowed to worship at mosques on a Home Office's list, the sources said.
The plan could also clamp down on the amount of time they spent at mosques, the sources said.
The tougher restrictions would form part of a plan to further restrict terror suspects' freedoms after Mohammed Ahmed Mohamed escaped from a London mosque by dressing in a burka earlier this month.
Pressure is mounting on the Government to explain how the al Shabaab-linked suspect managed to escape surveillance despite being the subject of a Tpim.
Defence Secretary Philip Hammond told Sky's Murnaghan programme that lessons needed to be learned from the case.
"The security services and the police face a huge challenge monitoring very large numbers of potential threat streams and we are acutely conscious that the terrorist only has to get lucky once - we have to get lucky every time," he said.
"Because of the large numbers of potential threats that we are monitoring and managing, it is inevitable that every now and again that one will slip through the net.
"When that happens we have to learn the lessons, we have to tighten the system."
Shadow Home Secretary, Yvette Cooper MP, said her Govermment counterpart Theresa May was "belatedly trying to close the stable door that she herself threw open" with the stricter measures.
"This Home Secretary repeatedly ignored warnings that ditching relocations would increase the risk that terror suspects would abscond," she said.
"After losing two out of the ten suspects she's been forced to admit there's a problem. But her hands are tied by her own legislation.
"If Theresa May has finally realised that she did the wrong thing by weakening terror controls, she should apologise. And David Cameron should take over the crucial decisions on terror suspects as its clear the Home Secretary can't be trusted to get it right."
A hunt involving the Metropolitan Police's counter terrorism command, MI5 and the UK Border Force has so far failed to track down Mohamed.
But he is not the first person to breach a Tpim since they were introduced to replace control orders in early 2012.
