Tony Blair is seeking the support of British Muslim leaders and Muslim and non-Muslim nations for fresh action to uproot the "evil ideology" and "twisted teachings" inspiring suicide bombers around the world.
At the same time, the British prime minister has signalled his readiness to rush new measures through parliament giving police extra powers to combat the incitement and instigation of terrorism - and to better enable the exclusion and deportation of religious extremists from abroad who might seek to stir up hatred in the aftermath of the bombings.
Confirming his "shock" that the capital's suspected suicide bombers were British-born, Mr Blair again joined forces with Opposition leaders Michael Howard and Charles Kennedy in calling for "the same measured and calm response from the country that has characterised it since last Thursday".
He told MPs: "This is a small group of extremists. Not one that can be ignored, because of the danger they pose. But neither should it define Muslims in Britain, who are overwhelmingly law-abiding, decent members of our society."
In another powerful display of bipartisanship, Mr Howard said that "anyone who nurtures resentment against our Muslim community is the enemy of us all".
Mr Blair and Mr Howard were speaking against a backdrop of what a senior police officer said was now "palpable fear" in the community, sparked by close to 100 faith or race hate incidents across Britain since the London bombings, which claimed the lives of at least 52 people.
Muslim leaders had already expressed their "anguish, shock and horror" at the news that the London bombers were thought to have been British nationals from their own community.
Iqbal Sacranie, secretary general of the Muslim Council of Britain, said the "criminals" who bombed London needed to be distanced from the Islamic faith.
"Nothing in Islam can ever justify the evil actions of the bombers," he declared.
Massoud Shadareh, chairman of the Islamic Human Rights Commission, said: "The criminality of anyone should not be associated with their nationality, ethnicity or religion.
"That sort of association is totally unjust and xenophobic and can create a great injustice by promoting prejudice that could fuel further violence against innocent people. A criminal is a criminal, is a criminal, full stop."
A group of British Muslim MPs also went to 10 Downing Street to tell Mr Blair of the shock and numbness in their communities upon learning that the London bombers were "home grown".
Glasgow MP Mohammed Sarwar said: "We expressed to the prime minister that all the Muslim communities are in shock. We are deeply shocked that these are home-grown bombers, and the vast majority of the Muslim community condemn these barbaric acts."
However, fellow Labour MP Shahid Malik told the Commons the current situation represented "the most profound challenge yet faced by the British Muslim community" and that "condemnation is not enough". Mr Malik said he believed British Muslims must, and were prepared to, "confront the voices of evil head on".
Later, on BBC Radio 4's World at One programme, Mr Malik said this meant now confronting unacceptable views which might previously have been considered "silly rhetoric" by people thought simply to be "lunatics".
The Muslim Council is supporting today's two minutes' silence at noon as a mark of respect for the victims of last Thursday's bombings, and this evening's planned vigil in Trafalgar Square.
In addition, the council said it had been planning an inter-faith national demonstration in protest at the bombings on London's transport network.
Mr Howard and Mr Kennedy confirmed they would join Mr Blair at a Downing Street summit with British Muslim leaders on Tuesday, while the prime minister stressed "the worldwide dimension" in seeking to mobilise "the moderate and true voice of Islam".
In talks with police, ministers are carrying out an urgent examination of ways to strengthen the process for excluding from the UK people who incite hatred, and to deport them where they have already entered the country.
Mr Blair said it was also vital to talk to other Muslim and non-Muslim nations to address the problem in countries "where the roots of this sometimes grow in some of the twisted teaching, in some of the violence that is taught at a very early age".
He insisted that ways had to be found to "pull up this evil ideology by its roots".
Mr Blair said: "I think it is very obvious to us, with the shock of knowing that those who have perpetrated this were actually born and brought up in this country, it is particularly important that we recognise the worldwide dimension and the need therefore to tackle it internationally."