Tony Blair has urged peers to back the anti-terror bill after MPs overturned a series of House of Lords amendments.
MPs voted down peers' amendments
Ministers saw off a bid to put a time limit on the controversial bill which returns to the Lords on Thursday.
They had already agreed to allow judges to oversee all control orders - from house arrest to less serious limits on freedoms such as internet access.
Mr Blair said it would be irresponsible to water down the bill further, and said police and experts backed it.
Burden of proof
He said: "The directly-elected House of Commons has now made its view very, very clear indeed.
"The security service and the police are advising us that this legislation is necessary to combat terrorism effectively.
"The Conservative Party - and even people on my own side - should stop trying to water this legislation down, dilute its effect, and understand it is necessary, it is right, to protect the civil liberties of the vast majority of people in this country who want to be protected against terrorism."
MPs also overturned by a majority of 89 a Lords amendment calling for a higher burden of proof for control orders despite 37 Labour MPs voting against the government including ex-cabinet ministers Clare Short and Frank Dobson.
Tory leader Michael Howard had accused Mr Blair of refusing to compromise so the bill would fail and he could then claim Labour were toughest on terror.
Lib Dem leader Charles Kennedy said Britons' civil liberties should be put before Mr Blair's personal political pride.
Ministers won a vote in favour of judicial involvement in all control orders and saw off the bid to increase the level of proof needed from "reasonable suspicion" of involvement with terrorism to "balance of probability".
Earlier at Prime Minister's Questions Mr Blair rejected calls for a "sunset clause" which would mean the bill lapsing in November.
LORDS' DEMANDS INCLUDE:
All control orders should be issued by a judge, not the home secretary
Standard of proof for control order rises from "reasonable grounds" for suspicion, to satisfaction on the "balance of probabilities"
Director of Public Prosecutions must state there is no reasonable prospect of successful prosecution before order is made
Use of evidence against terror suspects obtained under torture abroad prohibited
No additional forms of control order can be created
The legislation will expire on 30 November 2005
Mr Howard countered: "Is he simply saying he would prefer to have no bill at all than one that would last for eight months?"
Mr Kennedy called for further concessions and for those who have control orders imposed on them to be told what the allegation or evidence against them was.
Mr Blair said the security services had told him control orders and the proposed burden of proof were needed and that it would be "irresponsible" to go against that advice.
Home Secretary Charles Clarke told MPs the plans would be voted on annually by Parliament in the hope that this would meet demands for the "sunset clause".
But the Tories and Liberal Democrats both said Mr Clarke has not gone far enough.
The government brought forward the anti-terror bill after the Law Lords ruled against existing measures which allow foreign terror suspects to be held indefinitely in prison without trial.
Those existing powers, under which 10 people are still held, are due to run out on Monday. The government says it wants to replace them with the new anti-terror bill instead of renewing them.
The core of the bill is the introduction of control orders for both British and foreign terrorist suspects. They range from tagging to house arrest.
Initially it was proposed that the home secretary would be able to impose control orders, when there was "a reasonable suspicion" that a person was involved with terrorism.
The control orders are intended for cases where it would not be possible to prosecute someone in court - but where intelligence suggested the person posed a terror risk.
Opposition parties have been unhappy with the measures on a number of counts, and the plans suffered a series of defeats in the House of Lords this week.
The key objections were that judges, not politicians, should impose control orders, that the bill should be seen as a temporary measure that would lapse in November, and that the burden of proof should change from "reasonable suspicion" to "balance of probability".
For the Tories, David Davis said: "If we don't use the balance of probabilities we will have control orders on people who are probably not terrorists. If you want a formula for a miscarriage of justice that's it."
The Lib Dems also wanted the burden of proof to be on the "balance of probabilities" and also for suspects to be told what the charges against them are.