Political correctness is threatening British society, it has been claimed.

A book published by social policy think-tank Civitas blamed PC attitudes for creating "Muslim ghettoes" which produced "young men who commit mass murder against their fellow citizens".

Author Anthony Browne said "intolerant and sanctimonious" political correctness had led to censorship.

For example, adherents of PC blamed the explosion in the UK's HIV infection rate on teenagers having unsafe sex, when in fact the rise was largely down to the arrival of HIV-positive African immigrants in Britain, he claimed.

He also argued that women's pay was believed to be less than men's because of sex discrimination, when in fact it was due to women making different work-life choices and taking childcare breaks.

He also said of policital correctness: "By challenging the authority of teachers, it fuels poor discipline in schools, and by promoting equality over excellence, it degrades the standard of education and inflates exam grades until they become almost meaningless.

"Black communities are encouraged to blame racist teachers for the failure of their boys at school, rather than re-examine their own culture and attitudes to education.

"The Labour government tolerates the numerically far greater animal cruelty of halal slaughter, and bans the far less significant cruelty of fox hunting simply because the perpetrators of halal slaughter have victim status while fox hunters have oppressor status."