Tony Blair has told immigrants they have a "duty to integrate" and said immigrants should stay away unless they are prepared to accept Britain's traditional tolerance of other faiths.
The Prime Minister said it was "plain common sense" to ban face veils in jobs that depend on communication, dismissed suggestions that sharia law should be adopted anywhere in Britain and called on mosques that excluded women to "look again at their practices".
He also announced a crackdown on public money for ethnic minority groups that did not promote integration and urged faith schools to build bridges with other religions.
In a strongly-worded lecture on integration, Mr Blair mounted a wide-ranging defence of multiculturalism, but insisted that its success depended on Britons of all backgrounds respecting the nation's "essential values".
He singled out a "new and virulent form of ideology associated with a minority of our Muslim community" for threatening racial harmony in the United Kingdom.
"Most Muslims are proud to be British and Muslim and are thoroughly decent, law-abiding citizens. But it is a problem with a minority of that community, particularly originating from certain countries."
He drew a parallel between white supporters of the British National Party and Muslims who shun integration. Mr Blair complained that public money had been too easily handed out to organisations "tightly bonded around religious, racial or ethnic identities".
He added: "In the future, we will assess bids from groups of any ethnicity or any religious denomination, also against a test, where appropriate, of promoting community cohesion and integration."
The Prime Minister said that "equality of respect and treatment for all citizens" was a key British value.
He spoke of the frustration of some Muslim women at being barred from certain mosques and insisted: "Those that exclude the voice of women need to look again at their practices."
Mr Blair said that no British citizen could legitimately expect to stand outside the law as set down by Parliament. "There is no question of the UK allowing the introduction of religious law in the UK."
He said it was important faith schools taught "tolerance and respect" for other religions and announced that the Department for Education and Skills would examine ways of ensuring that happened. He added: "We will also encourage all faith schools to construct a bridge to other cultures by twinning with schools from another faith."
The Prime Minister re-entered the controversy over women wearing face veils by pointing out that Jack Straw's disclosure that he asked for them to be removed in constituency surgeries had been backed by the Mufti of Egypt, its interpreter of Islamic law.
"It is really is a matter of plain common sense that when it is an essential part of someone's work to communicate directly with people, being able to see their face is important."
Mr Blair defined British values as "belief in democracy, the rule of law, tolerance, equal treatment for all, respect for this country and its shared heritage".
Dominic Grieve, the Tories' community cohesion spokesman, described the speech as a remarkable turnaround. "Many of the problems ... he addresses are at least in part the consequence of a philosophy of divisive multiculturalism and political correctness that has been actively promoted by the Labour Party over many years at both national and local government levels," he said.Reuse content