Birmingham City Council "failed" headteachers of Birmingham schools by not tackling the "Trojan Horse" issue when it was originally raised with them more than two years ago, says a high ranking member of the National Association of Head Teachers (NAHT).

Rob Kelsall, senior regional officer at NAHT, welcomed today's government report, which found that authority figures in a number of Birmingham schools "espouse, endorse or fail to challenge extremist views".

It also found that governors of the implicated schools planned to "impose segregationist attitudes and practices of a hardline, politicised strain of Sunni Islam" on pupils.

Kelsall said: "We welcome the fact the government is looking at a mechanism by which governors who cross the line, going beyond their role of a critical friend.

"What we now need is a drawing of the line. We need to move forward to ensure the issues raised never occur again in any other school."

The investigation, ordered by former education secretary Michael Gove into the "Trojan horse" allegations in Birmingham originally made in April this year, concluded that there has been "co-ordinated, deliberate and sustained action" by a number of individuals to introduce an "intolerant and aggressive Islamic ethos" into a few schools in the city.

This has been achieved in some schools by radical Islamists gaining influence on the governing bodies, installing "sympathetic" headteachers and senior staff, appointing "like-minded" people to key positions and removing heads who were not "compliant" with a particular agenda, the report noted.

The inquiry has been conducted by former counterterrorism chief Peter Clarke, who gathered 2,000 documents and generated more than 2,000 pages of interview transcripts from 50 witnesses, including former headteachers, teachers, council staff and school governing boards. Clarke did not interview parents or pupils.

"The level of distress and anxiety felt by the witnesses cannot be overstated," Clarke said.

Clarke's 90-page report is released on the same day The Daily Mirror reveal they have exposed a Birmingham school chief as a "sexist, racist bigot" in an undercover sting.

Former chairman of governors at Nansen Primary School, Shahid Akmal, told an undercover Mirror reporter that "white women have the least amount of morals", white children were "lazy" and that British people have "colonial blood", writes Nick Sommerlad.

Manifestations of extremism in the schools outlined in the report include: anti-western rhetoric, particularly anti-US and anti-Israel, segregationism, perception of a worldwide conspiracy against Muslims, and attempts to impose views and practices upon others.

Clarke says: "Essentially the ideology revealed by this investigation is an intolerant and politicised form of extreme social conservatism that ultimately seeks to control all Muslims.

"In its separatist assertions and attempts to subvert normal processes it amounts to what is often described as Islamism."

Concerns have been raised that the report is Islamophobic but Clarke denies the accusation saying saying "the evidence shows a group of governors and senior teachers represented a form of Muslim extremism rejected by most Muslims in east Birmingham", reports The Guardian, who leaked an early version of the inquiry findings.