Shadow Home Secretary David Davis launched a stinging attack on Muslim leaders for risking "voluntary apartheid" in Britain and expecting special protection from criticism.
Mr Davis issued a stark warning of "closed societies" being created in Britain, and said religious divides threatened to "corrode" fundamental values such as freedom of speech.
There was a danger that the perfect conditions for "home grown terrorism" were being established, he added.
Mr Davis's comments - which appear to mark a hardening of the Conservatives' stance on tackling radical Islamism - came in an article for the Sunday Telegraph.
He wrote: "At its very least, there is a growing feeling that the Muslim community is excessively sensitive to criticism, unwilling to engage in substantive debate.
"Much worse, is the feeling of some Muslim leaders that as a community they should be protected from criticism, argument, parody, satire and all the other challenges that happen in a society that has free speech as its highest value."
Mr Davis accused the government of showing a "confused, confusing and counterproductive" attitude towards the problem of integration.
He expressed sympathy for Commons Leader Jack Straw's position on veils, but insisted that the problem went deeper, affecting the "very unity of our nation".
Former Home Secretary David Blunkett also urged open discussion of integration issues in an interview with the newspaper.
He said: "We should not go out of our way to avoid saying things that we want to say because we might actually cause a rumpus. I have always said what I think. I think that part of being in our society is that we all have to live with that."
