Tony Blair has denied claims by senior MPs and peers that he is "railroading" controversial house arrest plans through Parliament.
Mr Blair says he is trying to protect national security
He said he was "not being arrogant" - he was just trying to protect the country from a terrorist attack.
Mr Blair suggested he might be able to compromise on opposition demands for judges to be given a greater role.
But he insisted he would stand by the principle of imposing restrictions on suspects who cannot be tried.
The Prevention of Terrorism Bill proposes "control orders", which as well as house arrest could impose curfews, tagging or bans on telephone and internet use.
They would replace current powers to detain foreign terror suspects without trial, which the law lords have ruled against.
Liberal Democrats and many Labour backbenchers want judges - and not politicians - to issue the control orders in the first place, while the Tories have more wide-ranging objections to the plans.
The proposed legislation has also come in for strong criticism from MPs and peers in a report by the Joint Committee on Human Rights.
It said there could be "no justification" for including such wide and unprecedented powers in legislation "which is being rushed through parliament at a speed which prevents proper scrutiny".
The Bill is expected to clear its next Commons hurdle on Monday, but without opposition support it could be thrown out by the Lords.
Speaking at his monthly press conference, Mr Blair said control orders were "absolutely necessary".
"I'm not being arrogant or railroading things through, I'm just trying to protect the security of our country," he said.
Home Secretary Charles Clarke is discussing the Bill with Labour backbenchers and other parties in an attempt to reach the "broadest possible basis of consent", said Mr Blair.
Addressing concerns about who should impose the orders, he said: "It is important to emphasise that we were never going to take the judge out of this."
The prime minister said the powers were targeted at a small number of people who were "a real threat" and whose activities the security services "want to interrupt", but "where we don't actually have the sufficient evidence to prosecute them and arrest them for conspiracy to commit a terrorist act".
A spokesman for the Liberal Democrats said the party was "encouraged that the government seems to be willing to make some movement on the involvement of a judge".
But he said the offers so far fell "well short" of ensuring it was a judge who made the order to detain a person, and not a politician.