Chancellor Gordon Brown said the UK must "wake up" to the complexity and global scale of the terror threat.
The police followed up some 12,000 leads after 7 July, said Mr Brown
He was speaking on the eve of a major speech in which he will announce a raft of new security measures.
Plans for an integrated electronic border system will be unveiled as well as a proposal to extend the time terror suspects can be held without charge.
But the Conservative leader David Cameron has accused the government of "ineffective authoritarianism".
On Monday Mr Brown is expected to announce a public review which will focus on counter-terrorism and security.
'The British way'
Interviewed on the BBC's Sunday AM programme, the chancellor said: "We have to be tough on security measures but the British way of doing it is to be both tough on security measures and to build in proper systems of accountability to Parliament that can give protection to people's individual civil liberties."
Talking of the measures taken to combat terrorist actions and the police investigations following the 7 July bombings, he said: " "People have got to wake up to the complexity, the scale, the global nature of this."
"I do feel that some people who are opposing us on these issues have got this wrong," he added.
While accepting the "a will of parliament" on the issue of 28 days detention for terror suspects, the chancellor said he believed there was a "case for going beyond 28 days".
Investigations after the 7 July attacks had involved looking at some 50 internet sites, following about 12,000 leads, he said.
Mr Brown told Sunday AM "the world has changed" and the issue of ID cards and biometrics, with built in safeguards for civil liberties and accountability to parliament, would be acceptable to most people as the way forward.
Pointing out that Mohammed Atta, the leader of the September 11 attacks - and the pilot of the first plane to hit the Twin Towers - used a false identity, he said: "It is a protection of people's individual civil liberties that we do not allow easily people to multiply their identities or operate on false identities."
Among his proposals are:
- an integrated electronic border security system to check biometric passports at ports and airports
- a single security budget - which could mean a new department for homeland security
- new measures to combat the financing of terror networks, with private and public sectors sharing data
- the 28 days for holding terror suspects without charge to be extended
Mr Brown said three terror plots had been disrupted since 7 July and he added that the threat had not gone away.
Mr Brown's forthcoming speech on terror is seen as a move into new territory by the chancellor, who is tipped to succeed Tony Blair as prime minister.
During his interview on Sunday AM, Mr Brown denied he and Mr Blair were operating a "dual premiership".
"There is no arrangement such as that," he told interviewer Andrew Marr.
"Tony Blair makes the decisions as prime minister ... I get on with my job as chancellor."
He said they were both addressing the "long-term issues facing the country".