Labour MP Pat McFadden said the move to put in place reduced powers was “complacent and dangerous”.
The criticism came after suspected terrorist Ibrahim Magag went on the run on Boxing Day.
Magag, 28, absconded from a Terrorism Prevention and Investigation Measures (Tpims) notice after failing to meet his overnight residence condition, police said.
He was last seen in the Camden area of north London on the same day at 5:20pm.
An anonymity order imposed by a court was lifted to allow a public appeal.
Mr McFadden said the government had put the public at greater risk by watering down the previous control orders regime.
He said: “I think what they have done is complacent and dangerous, and I warned the Home Secretary and the Prime Minister about this when the legislation was going through.
“He has used his new-found, government-given freedom to come back to London and has now absconded. What they have done is put the public at greater risk by watering down our anti-terror laws.”