Politicians and the media have become "terrified" of discussing race issues and multiculturalism has become a "racket", according to a former equality chief.

Trevor Phillips, a former chairman of the predecessor to the Equality and Human Rights Commission, suggested some ethnic groups had become "isolated" and politicians' unwillingness' to address the issue had led to the rise of "angry, nativist political movements".

His comments come ahead of his documentary, called Things We Won't Say About Race That Are True, being aired on Channel 4 and after revelations that Ukip leader Nigel Farage, in an interview for the film, intimated he would scrap race discrimination legislation.

Writing in the Daily Mail, Mr Phillips said: "The perverse and unintended consequences of our drive to instil respect for diversity is that our political and media classes have become terrified of discussing racial or religious differences. Our desperation to avoid offence is itself beginning to stand in the way of progress. And all too often the losers are minority Britons.

"Preventing anyone from saying what's on their minds won't ever remove it from their hearts. People need to feel free to say what they want to without the fear of being accused of racism or bigotry."

He cited the child sex abuse scandals in several UK towns including Oxford, Rotherham and Rochdale and the murder in 2000 of eight-year-old Victoria Climbie as examples of institutions failing to act for fear of offending minority groups.

Mr Phillips, a Labour London Assembly Member, also admitted he felt he bore some responsibility for the July 7 bombings in 2005 because, as then head of the Commission for Racial Equality (CRE), he failed "to see what was coming".

He said: "Because I had made it my business to spend part of each week in a community outside London, I already knew some groups were becoming so isolated that values and ideas which most people would find alien were tolerated and even encouraged.

"But we had said little about it and done even less. After 12 months at the CRE I had come to the conclusion that, while beautiful in theory, multiculturalism had become a racket in which self-style community leaders bargained for control over local authority funds that would prop up their own status and authority.

"Far from encouraging integration it had become in their interest to preserve the isolation of their ethnic groups."

Right-wing political movements which have surged in support across Europe, such as the National Front in France, were a fuelled by political correctness, Mr Phillips added.

In the documentary Mr Farage, when asked if he would retain bans on discrimination on the grounds of race or colour, said: "No... because we take the view, we are colour-blind. We as a party are colour-blind."

But he later moved to clarify his comments, which drew cross-party condemnation, saying in a statement: "My comments to Trevor Phillips were lauding the progress of race relations and equality in this country. Britain's media should be proud of this fact instead of trying to do it down.

"Ukip is the only party that is suggesting that Britain's employers should be free to employ British workers, regardless of creed or colour."

The documentary is to be aired on Channel 4 on Thursday at 9pm.