Last year, Birmingham city council said it had received an anonymous letter detailing plans by Islamic extremists to take over state-run schools.
The letter, which was first seen by the council in November 2013, outlined a five-point "Trojan Horse" strategy to infiltrate the schools, including using hardline "Salafi" Muslim parents to replace school governors and force the resignation of existing head teachers.
Trojan Horse report concludes there's no systematic plot, but allegations in letter are otherwise true. See summary >
The letter resulted in the "Trojan Horse" affair, after the council said it had received "hundreds" of reports from school staff about the hijacking of schools by Islamic radicals.
These included accusations of some schools teaching Quranic Arabic classes, encouraging students to recite an Islamic prayer before classes, and even bringing in "inappropriate" external speakers to lecture students.
Since June 2014, five different investigations of Birmingham schools have taken place, by authorities including the schools watchdog Ofsted, the Educational Funding Authority, West Midlands Police and Birmingham City Council.
Five schools were placed under special measures as a result of the investigation –including two schools formerly classed as "outstanding" – because they had not "sufficiently protected their pupils from extremist views and activities".
The then education secretary Michael Gove subsequently introduced new measures to combat "Islamification" in British state schools.
Gove told MPs that schools would be made to promote "British values", including teaching civil law and religious tolerance. Gove also said that concepts like "opposing gender segregation in classrooms" would also be taught.
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However, in a report published on Monday, a cross-party group of MPs rejected the claims that any "Trojan Horse" plot had taken place.
In the report, the MPs said:
No evidence of extremism or radicalisation, apart from a single isolated incident, was found by any of the inquiries and there was no evidence of a sustained plot nor of a similar situation pertaining elsewhere in the country.
They also found that the inquiries had affected the academic performance of pupils in the schools.
The MPs said there had been a "worrying and wasteful lack of co-ordination" between the inquiries, and because some had overlapped, they had created "a sense of crisis and confusion" in the schools.
According to the Birmingham Mail, the proportion of pupils at Park View school gaining five or more A*-C grades at GCSE fell from 75% in 2013 to 58% in 2014.
In the report, the MPs said:
The children in the schools affected in Birmingham deserve better from all involved.
It is important to return to the need to ensure a good education for the children at the schools affected. They, and their schools, will continue to require support from local and central agencies to make this a reality.
One Birmingham parent, who did not wish to be named, told BuzzFeed News that his daughter had been one of those affected.
"Teachers have been less focused on teaching, and are more worried about whether the investigation will leave them jobless," he said.
"When you don't have teachers that are focused, how can you expect the students to concentrate on your work? It can't happen."
He added: "My daughter used to be an A and A+ student, now she's getting Bs and Cs. That happened in less than a year, and there's got to be a reason for that. It doesn't happen on its own."
The report also criticised the methods used by Ofsted during the investigation.
Questions have been raised about the appropriateness of Ofsted's framework and the reliability and robustness of its judgements. Ofsted must act to restore confidence in the inspectorate.
The British values which are now to be promoted in all schools are universal and deserving of support. Monitoring how these are promoted in individual schools must be done with common sense and sensitivity.