Gillian Shephard, the Education and Employment Secretary, has upheld the ballot result at Trinity Roman Catholic comprehensive where parents voted five to two in favour of the school becoming grant-maintained.
She described the incident where parents only received letters from governors and the local authority after they had been sent ballot papers as "unfortunate" but said it was not enough to declare the result void. Other complaints, which included the LEA not being able to hold a meeting for parents at the school and disagreements over the funding the school would get if it went GM, were also dismissed.
But civil servants said Mrs Shephard considered that "it would have been preferable for the governors to have provided more information for parents and more opportunities for them to explore the implications of GM status".
Her decision to allow the school to opt out comes after a seven-month wrangle over the ballot following complaints from the Association of Teachers and Lecturers, Nottinghamshire County Council and some parents.
It follows her approval last month of GM status for Arthur Mellows Village College in Peterborough - a comprehensive school in John Major's constituency - despite her admission that parents were given misleading information.
Ralph Surman, Nottinghamshire branch secretary of the ATL, said: "How can any party in government admit these kind of mistakes and at the same time uphold the ballot decision? There is something fundamentally wrong here. This is the Government's education bandwagon and the Department for Education and Employment will let anyone jump on it at any cost.
"The Government should be above any kind of greyness or fudged edges. There should be clear-cut procedures and that is what I think is lacking. Legislation has got to be tightened up."
Bernard Bonner, head of Trinity RC comprehensive, said he expected the school would go GM on January 1 and said: "We knew we had done everything correctly. We expected to find that the result was upheld."