Mrs Maguire’s family have instructed lawyers to apply for a judicial review into what they say is the decision by West Yorkshire coroner David Hinchliff to exclude evidence and witnesses from the hearing.
An inquest examining the circumstances leading up to the fatal stabbing at Corpus Christi Catholic College in Leeds in April 2014 had been due to take place this week, but now has a provisional start date of November 13.
The 61-year-old Spanish teacher was stabbed to death by student Will Cornick, who was later jailed for life with a minimum of 20 years at Leeds Crown Court.
A statement issued by law firm Irwin Mitchell, which is representing the family, said they are “concerned that the hearing is not currently planning to review all the relevant evidence and hear from all relevant witnesses”.
It said the family was told in 2015 that no Serious Case Review would be held over the death and that a Learning Lessons Review (LLR) was completed in November 2016, more than two years following the incident.
It added: “However at a recent pre-inquest review it was revealed that many of the conversations during the LLR were not recorded or written down and the family has concerns over how thorough the process was.”
Yogi Amin, a partner at Irwin Mitchell, said: “The family have many unanswered questions and hoped that a full inquest, held in public, would examine the full chain of events and all the evidence available so that lessons could be learned to reduce the risk of similar incidents happening again.
“Ann Maguire’s family have from the outset asked for a thorough, full and independent investigation into the horrific events that led to her murder by a pupil whilst she was teaching in the classroom.
“They believe this would be the best use of time and public resources.
“However they have become very concerned about the scope of the full inquest hearing scheduled for later this year.
“The police investigation was itself limited in scope as the defendant quickly admitted responsibility meaning there was no examination of all the evidence publicly.
“The family want to know the full facts and hope that they will still be able to get the necessary answers through an independent and fair process at the Inquest.”
The learning lessons review, carried out by the Leeds Safeguarding Children Board, concluded that “no one could have predicted or pre-empted Will Cornick’s attack on Ann Maguire”.
It included an account by Cornick of how a “red mist” descended on him in the minutes before he committed one of the most shocking crimes in recent British history.