Communities Secretary Ruth Kelly today called for a "new and honest debate" on the value of a multi-cultural society in Britain.
Launching the Government's Commission on Integration and Cohesion, she warned there was a danger that communities were becoming increasingly isolated from each other.
"We have moved from a period of uniform consensus on the value of multi-culturalism to one where we can encourage that debate by questioning whether it is encouraging separateness," she said at the launch in south London.
"They are difficult questions and it is important that we don't shy away from them.
"In our attempt to avoid imposing a single British identity and culture, have we ended up with some communities living in isolation from each other with no common bonds between them?"
The decision to establish the commission, to improve community cohesion and tackle extremism, was originally taken in the wake of last year's July 7 bomb attacks in London.
While Ms Kelly said diversity had been a "huge asset" to Britain, she warned that, as new waves of immigrants came into the country, international events increasingly impacted on community relations.
"Global tensions are being reflected on the streets of local communities," she said.
She also warned of the dangers of white Britons becoming alienated by the pace of social change.
Detached from the benefits of those changes, they begin to believe the stories about ethnic minorities getting special treatment and to develop resentment - a sense of grievance, she said.
Ms Kelly called for an "open and honest" debate on community cohesion.
"We must not be censored by political correctness and we can't tiptoe around the issues.
"For example, it's clear that we need a controlled, well-managed system of immigration that has clear rules and integrity to counter exploitation from the far right," she said.
Adding that she agreed with Home Secretary John Reid that it was "not racist" to debate immigration and asylum, Ms Kelly went on to say that such discussions should be based on "fact and not myth".
"Our ideas and policies should not be based on special treatment for minority ethnic faith communities.
"That would only exacerbate division rather than help build cohesion.
"And as a society, we should have the confidence to say 'no' to certain suggestions from particular ethnic groups but, at the same time, to make sure everyone can be treated equally, there are some programmes that will need to treat groups differently," she said.
But the Secretary of State added that "with rights come responsibilities".
"Even within the framework of mutual tolerance, I believe that there are non-negotiable rules understood by all groups," she said.
"Those who seek to cause conflicts and tension in our communities must be marginalised by the responsible majority.
"That means everyone needs to be involved."
Darra Singh, the chairman of the new commission, said there was not a lot of time before they were due to report next June, but added he was convinced they would come back with "a report and a set of practical recommendations that can set communities up for the longer term".
"There's no more important issue than how we get on with our neighbours."
He added that the emphasis of the work of the commission had to be on practical suggestion, not just "sitting around a table posing questions".
"I am convinced that the commission can help local communities to bring about change.
"I know this is going to be a very tough task," he said.
The commission will have to both "foster debate" while also finding solutions which "are grounded in reality".
He added that he hoped the commission would involve "women, young people and establish communities who may not think that integration is an issue for them".