More than half of Muslims in Britain think homosexuality should be illegal, while 47% believe teachers should not be gay, a survey has revealed.
A poll carried out by ICM also found that only 34% of British Muslims would tell the police if they thought someone they knew was getting involved with supporters of terrorism in Syria.
Commissioned for Channel 4 it will feature in a documentary called What British Muslims Really Think, presented by Trevor Phillips - former Equality and Human Rights Commission chairman.
The survey was carried out to try and understand what British Muslims - not their representatives - think, and to discover why some young Muslims are being drawn to violence.
When asked to what extent they agreed that homosexuality should be legal in Britain, 52% said they disagreed, and 47% said it was unacceptable for a gay or lesbian person to teach in school.
Of the 1,000 people surveyed, 23% said they would support there being areas of Britain in which Sharia law was introduced instead of British law.
Four per cent of those polled said they sympathise with people who take part in suicide bombing to fight injustice.
More than one third - 39% - were also found to be of the view that "wives should always obey their husbands".
A large majority of British Muslims, 86%, said they felt a strong sense of belonging to Britain, with 94% saying they felt they were able to freely practise their religion.
Responding to the findings, Mr Phillips said they pose profound questions for society and the implications for future relations between Britain's Muslim and non-Muslim communities.
He added: "Hearing what British Muslims themselves think, rather than listening to those purporting to speak on their behalf, is critical if we are to prevent the establishment of a nation within our nation. Many of the results will be troubling to Muslims and non-Muslims alike - and the analysis of the age profile shows us that the social attitudes revealed are unlikely to change quickly.
"The integration of Britain's Muslims will probably be the hardest task we've ever faced. It will require the abandonment of the milk-and-water multiculturalism still so beloved of many, and the adoption of a far more muscular approach to integration."
ICM used face-to-face, in-home research to question a representative sample of 1,000 Muslims across Britain.