Mrs Maguire’s loved ones have spent months trying to secure a judicial review of a decision by assistant West Yorkshire coroner Kevin McLoughlin regarding the scope of her forthcoming inquest.
Mr McLoughlin has said that it will not hear evidence from students who had contact with the mother-of-two’s killer, Will Cornick, immediately prior to the murder.
The family’s application for a review of his decision was rejected at the High Court in London over the summer.
And today three judges at the Court of Appeal dismissed their bid to overturn that ruling.
Lord Chief Justice Lord Burnett, Lord Justice Treacy and Lord Justice Hickinbottom said they would give their reasons for their decision at a later date.
Mrs Maguire’s widower, Don, was in court in London for today’s appeal proceedings.
The family’s counsel, Nick Armstrong, told the judges: “This is the only occasion on which a teacher has been killed by a pupil in a British classroom.”
He said that the Maguires were “anxious that all lessons that can be learned from this tragedy, are learned”.
Mr Armstrong also said they believe the inquest will not provide any “meaningful” public airing of the circumstances of the murder.
Mrs Maguire, 61, was stabbed at Halton Moor’s Corpus Christi Catholic College in April 2014.
Cornick, a pupil at the school, was later jailed for life with a minimum term of 20 years.
The hugely-popular teacher’s inquest is due to take place before a jury at Wakefield Coroner’s Court, starting on Monday, November 13.
Rejecting the Maguire family’s judicial review application at the High Court in August, Mr Justice Holroyde said: “I have much sympathy for the claimants, and I fully understand their reasons for wishing to pursue this line of inquiry.”
But he said he was “unable to accept the submission that the assistant coroner reached a decision which was so seriously flawed as to be ... unreasonable”.
Prior to today’s hearing, Yogi Amin, a partner at law firm Irwin Mitchell, which is handling the Maguires’ case, said: “This appeal represents the next step in the family’s long-running battle to attain a full and fair inquest into the murder of Ann.”
A Leeds Safeguarding Children Board (LSCB) learning lessons review concluded last year that Mrs Maguire’s killing could not have been predicted or pre-empted.
Mr Maguire, who has called for a full independent inquiry into the death of his wife, believes the “bare minimum” was done in producing the LSCB report.