Michael Gove’s appointment of Peter Clarke, former head of the Met’s anti-terrorism unit, to head the “Trojan Horse” investigation in Birmingham was a sign of how serious this issue is, and how far it may extend beyond the normal remit of the DfE.  It is reasonable to think that Mr Clarke is not one of Mr Gove’s immediate circle of acquaintance, and that his name did not occur to the Secretary of State or to one of his advisers in a flash of inspiration. This is a Government rather than a personal appointment, probably taken on advice from the security services, and a clear indication of the stakes involved.

Mr Clarke, unlike the local NUT branch, is unlikely to believe everything he is told. This is a helpful start, as jihad permits any form of deception, and its proponents have had plenty of opportunity to practise since their successful removal of Ray Honeyford as head of a Bradford primary school in the eighties.

Extremist infiltration of free schools and academies was an obvious danger from the beginning, and I was happy to lead a Policy Exchange investigation into how it might be countered. It recommended extensive powers to vet, approve and remove governors for the Secretary of State, with special measures procedures accelerated so that these could be replaced or schools shut down very quickly if they were breaking the terms of their agreements with the DfE.

Such powers were embodied in legislation, and went further than any previously taken by a Secretary of State. So, if we can assume that the reports leaked to the Telegraph are accurate, what exactly has gone wrong? The answer almost certainly lies in the way the Secretary of State’s powers have been administered by the Department.

The Policy Exchange report began with the assumption that they would be exercised vigorously at the vetting stage, and that anyone with a hint of sympathy for extremism would be detected and eliminated. There was no right to become a governor, and just saying that you had given up previously held views would cut no ice. The history and personal views of those at the centre of the investigation suggest that either vetting has not been carried out, or that the Department has not taken enough notice of it. The British tradition of tolerance and benefit of doubt is a boon to infiltrators, and ruling it out in these circumstances has probably not been enough to stop it from operating in the minds of civil servants, and perhaps even ministers.

Extremists have exploited our “innocent until proved guilty” principle to their great benefit, and it was to be expected that they would do so here. They continue to supply alleged quotations of unprofessional comments by inspectors, such as, “We are going to fail you,” a remark that no trained inspector would make at the beginning of an investigation, which the local NUT branch accepts as gospel truth, and which circulates in a petition (which I’ve just been invited to sign) criticising the inspectors’ approach. Sir Michael Wilshaw is to visit Birmingham to see for himself, and will no doubt be forearmed.

The politics of relations with Islamism in Birmingham are complex, but have essentially been based on appeasement. The Guardian has carried comments by Salma Yaqoob, now Labour but the former leader of the Respect Party; by Chris Sims, Birmingham Chief Constable; by Birmingham City Council, the local Bishop, and, unsurprisingly, by governors from the schools under investigation describing the whole affair as a McCarthyite hoax, provocation and witch-hunt – with only Tristram Hunt, Labour’s Shadow Education Secretary, injecting a note of realism by making it clear that such activities are unacceptable.

Andrew Gilligan clearly has a high-level source for his disclosures and there will surely be more to come. In the meantime, we can hope that Mary Bousted, the union leader, is right in describing Mr Clarke’s appointment as “politically motivated.”  What is needed here is someone who understands the overt and covert politics of the situation, and has the skills and determination to sort it out.