A new poll of British Muslims revealed attitudes on homosexuality and terrorism sharply out of step with broader public opinion, but also set off a debate about the reliability of such surveys.

The survey was conducted by the polling company ICM Unlimited and commissioned by the British network Channel 4, which showcased its results in a documentary broadcast on Wednesday. The network said that the findings showed that the mainstream Muslim majority shared many values with non-Muslim Britons but warned that more extreme views lurked beneath the surface.

“Looking deeper into the results, a chasm develops between those Muslims surveyed and the wider population on attitudes to liberal values on issues such as gender equality, homosexuality and issues relating to freedom of expression,” the network said in a statement. “And it also reveals significant differences on attitudes to violence and terrorism.”

Trevor Phillips, the former chairman of the Equality and Human Rights Commission, analyzed the results for Channel 4 and said in a statement that they showed Britain faced a threat of “the establishment of a nation within our nation.”