The Court of Appeal quashed Education Secretary David Blunkett’s direction that governors at Woodhey school, Ramsbottom, Bury, hold a third disciplinary hearing after twice reinstating Anthony McNally, 51.

Bury education authority had pursued the case with successive secretaries of state, insisting that its representative should have been present during the governors’ deliberations.

But three top judges said it would have been against “natural justice” for an education authority representative, who had presented evidence against Mr McNally during the hearing, to take part in the closed discussions afterwards.

Nigel de Gruchy, general secretary of the National Association of Schoolmasters Union of Women Teachers, which took up Mr McNally’s case,said: “It’s a classic case of justice delayed, justice denied. We have established an important precedent - that you can’t be the member of a prosecution team and then take part in the discussions after the other parties have withdrawn.”

The NASUWT will be discussing Mr McNally’s future with Bury, and may seek compensation if a return to teaching proves difficult. A Bury spokesman said it was considering the judgment , and was awaiting further direction from Mr Blunkett.

A Department for Education and Employment spokesperson said Mr Blunkett “was in a difficult position between the warring parties of the LEA and the school”.

“We considered it was in everyone’s interest to have the matter reheard under the correct procedure, rather than have Mr McNally return to the school under lingering and potentially disruptive concerns about his suitability,” the spokesperson said.