The political battle over anti-terror laws has run all night and into the morning, with peers twice refusing to give up amendments to the bill.
Parliament has been debating the bill through the night
The House of Lords wants legislation to lapse later in the year and a higher standard of proof before restrictions can be placed on suspects.
But the government says the public want the laws for their own protection.
Home Secretary Charles Clarke refuses to back down, saying peers' "digging in of heels" is "unconstitutional".
"The Lords should not simply block [the bill] but recognise the elected chamber's right to the terrorist legislation," he said.
But Liberal Democrat Leader Charles Kennedy accused the government of "putting a gun to the head" of opposition parties over its anti-terror legislation.
Standard of proof: 182 to 111 (maj 71)
Rejected by Commons: 298 to 216 (maj 82)
Reinstated by Lords: 153 votes to 98 (maj 55)
Review of law: 178 to 110 (maj 68)
Rejected by Commons: 310 to 207 (maj 103)
Reinstated by Lords: 155 to 97 (maj 58)
Sunset clause: 192 to 107 (maj 85)
Rejected by Commons: 307 to 212 (maj 95)
Reinstated by Lords: 164 to 96 (maj 68)
Under the proposed Prevention of Terrorism Bill "control orders" ranging from tagging to house arrest could be imposed on both British and foreign terrorist suspects.
The government says it is necessary for national security, but opposition politicians are concerned about civil liberties.
There are now three main issues being debated by Parliament.
The Lords want a time limit, or "sunset clause", after which the law would lapse.
They want the Privy Council, a group of senior politicians, to review the law.
And they want a higher standard of proof - "balance of probabilities" instead of "reasonable grounds for suspicion" - before control orders could be given.
Home Office Minister Hazel Blears opened the 0120 GMT Commons stage with minor concessions on the bill, but refused to back down on any of the Lords' three major demands.
'Full of imperfections'
Concessions previously offered by ministers include an annual renewal of the bill and that judges, not politicians, should make the final decision on the imposition of all control orders.
On Thursday Tony Blair again urged the peers and opposition MPs to back the bill.
But Tory leader Michael Howard said the bill was "full of imperfections".
Lib Dem home affairs spokesman Mark Oaten said that while they accepted the need for control orders, the legislation as it stood was unsatisfactory.
The bill is to replace current law expiring on Sunday, under which nine foreign terror suspects are currently held, one under house arrest. A tenth was freed under strict bail conditions on Thursday.
If the bill falls it is expected that those measures - deemed to break human rights laws - would be extended for a short period.
The control orders are intended for cases where it would not be possible to prosecute someone in court.
Thursday's debate could be extended until Sunday if need be.