Ruth Kelly has today launched the government's new commission on integration and cohesion, promising that it will not be "censored by political correctness".
The communities secretary said there must be an "open and honest" debate about the effect of immigration on British society, particularly in the wake of the September 11th attacks in New York and last summer's bombings in London.
She reiterated home secretary John Reid's statement earlier this month that it was not "racist" to talk about immigration, and noted that the issues of integration and cohesion must be considered by all communities, not just those comprising ethnic minorities.
"I think we should celebrate and clearly articulate the benefits diversity have brought. But we must also recognise that the landscape is changing and we should not shy away from the difficult questions that arise," Ms Kelly told a meeting in London this morning.
"It is time to engage in a new and honest debate about integration and cohesion in the UK.the context of today's society arguably poses some of the most complex questions we have faced as a nation."
She indicated that the commission's research, which is due to be published next summer, could conclude that multiculturalism, where communities are encouraged to preserve their individual customs and values, is no longer a valid policy for 21st century Britain.
"We have moved from a period of near uniform consensus on the value of multiculturalism, to one where we can encourage that debate by questioning whether it is encouraging separateness," Ms Kelly said.
"In our attempts to avoid imposing a single British identity and culture, have we ended up with some communities living in isolation from each other?"
She stressed that while everyone in the UK was entitled to the same rights, they also had a responsibility to conform to certain values. This will be taken as a warning to Muslim communities who failed to condemn the London suicide bombings.
"There are non-negotiable rules, and we must be clear and unafraid to say that we expect these will be shared and followed by everyone who lives here," Ms Kelly argued.
The new commission is charged with looking at local initiatives that have been found to improve integration within and between different communities, such as school twinning schemes where young people from different backgrounds take part in shared events.
It will specifically look at the role of local government in preventing and diffusing any tensions that may arise, explaining that this can be achieved not by giving special treatment to specific groups, but by balancing diverse community interests.
In particular, Ms Kelly and the commission's new chairman, Darra Singh, stressed that integration was an issue for all communities, not just those made up of ethnic minorities.
"Those who seek to cause conflict in our communities must be marginalised by the responsible majority. Everyone must be involved, and we must recognise that there is more that binds us together than pulls us apart," Ms Kelly said.