The Green Party says Education Ministry documents reveal the Government was planning the closure of a Nelson’s Salisbury School more than a year before consultation began.
However, Education Minister Hekia Parata has rejected the Greens’ claims.
Late last year the High Court ruled Parata's decision to shut the residential school for girls with severe intellectual and physical disabilities was unlawful.
Parata announced an initial decision to close the school in August last year, after a three month consultation.
Green Party co-leader Metiria Turei said the documents, which date from May 2011, show the consultation was "a sham".
"All along Hekia Parata has pretended to have an open mind about the schools, but these documents, filed in the High Court, show that Salisbury never stood a chance. The consultation was a sham," Turei said.
Parata wanted to transform all boys Halswell Residential College into a co-educational facility and move the Salisbury students there. The school argued it would leave the vulnerable girls open to abuse.
The High Court ruling agreed the decision did not take into account the girls' safety.
The school believed Parata did not intend to retain the school beyond 2014 and asked Prime Minister John Key to appoint another minister to oversee any decisions.
The papers, obtained by the Greens, show officials planned to work with the board and principal of Halswell.
In the advice they wrote: "We also agree with your comment that the principal of Halswell would be an ideal person to be involved in any future changes ... we would expect [Salisbury] to resist change initially."
Education Ministry officials also sought $1.9 million for redundancies for affected staff.
Parata said the consultation was ‘‘genuine, inclusive, and responsive’’.
‘‘It was not a sham.
“We went into this process to raise the quality of provision, to expand the service to include more young people, and to provide personalised plans that recognised that these young people live their lives in their homes and their community.
“The consultation included a range of options, one option was actually to close all four residential schools. However the feedback we received convinced me to keep two of the four schools open, and at the same time extend the Intensive Wraparound Service.
“We did not make any decisions until August 2012. I became Minister of Education in December 2011 and received no reports specifically on residential schools prior to February 2012. My response to the February 2012 report was to agree to the ministry consulting with the education sector on options.’’