Some Muslims lead such separate lives that they believe Britain is an Islamic country where the majority of people share their faith, according to a report to be published this week.
Evidence gathered by Dame Louise Casey, the government’s community cohesion tsar, will lift the lid on how some Muslims are cut off from the rest of Britain with their own housing estates, schools and television channels.
Her report finds that thousands of people from all-Muslim enclaves in northern cities such as Bradford, Dewsbury and Blackburn seldom, if ever, leave their areas and have almost no idea of life outside.
A source who has read the report said: “Certain Muslims, because they are in these communities and go to Muslim schools, think Britain is a Muslim country. They think 75% of the country is Muslim.”
The correct figure, according to the 2011 census, is 4.8% of the population in England and Wales. Christians account for 59.3%.
Casey’s report will be embarrassing for ministers, and Theresa May in particular, because it will say the government does not have any serious integration strategy.
The report will criticise the Home Office, which May used to run, and other departments for not doing enough to manage the pace and consequences of mass immigration.
“It will say that nobody has been on it,” said a source familiar with the contents.
A source close to Casey said: “There is a desire [among policymakers] to tolerate such a level of significant difference that you have overcompensated and gone way too far.”
Those familiar with the report say Casey, who investigated failings by children’s services at Rotherham council after the child abuse scandal, has seen off attempts by the Home Office to water down her report. One described it as “full-fat Louise”.
The report will “send shock waves through the system”, a Whitehall source said, adding: “It’s going to be quite hard reading for some people.”
Casey will attack the police and other state bodies for “weakness” and pandering to false notions of what they think ethnic communities want — such as a police chief who said female officers could be allowed to wear the full veil.
“The report will say that we are in a vicious circle where some institutions are so wrongfully interpreting their version of political correctness that they are gifting the far right,” a source said.
Sir Michael Wilshaw, the departing chief inspector of schools, warns today that about 500 schools in England are either 100% white or 100% ethnic minority — and pupils in them are at risk of alienation and radicalisation.
Wilshaw told The Sunday Times that parallel communities were developing in Britain and children growing up in monocultural schools in these communities were in danger of being cut off from British values and vulnerable to either far-right or Islamist causes.
The chief inspector said that he was particularly worried about a cluster of 21 schools in Birmingham — many of them primaries with predominantly Muslim pupils — where there were no white pupils. Nearly half of the schools have been judged “less than good”.
“We have to make sure these schools are good schools so youngsters in them feel they are part of British society and they have to respect other people’s faiths and cultures,” Wilshaw said.
“In white-only schools the same thing applies. Though we might not be as concerned in white communities about radicalisation, certainly we are worried about alienation and the rise of the far right.
“If these children have not been well educated and cannot get jobs as a result that will feed into alienation and the espousal of right-wing ideologies.”
Casey has examined the social alienation felt by the white working class. Although her report will not dismiss the far right it will say that Islamist extremists pose a more serious threat.
The report will also attack the government for not doing enough to defend Prevent, its embattled counter-extremism policy, against misinformation put out by Islamist and far-left groups.