She has called for further details of the sacking of Philip Bond, former chairman of governors at Waltham Toll Bar comprehensive school in Grimsby, before reaching a final decision.

Meanwhile, the vice-chair of the governing body, who also supported the opt-out attempt, seems to have survived a move to oust her.

Governors opposed to opting out, who are now in the majority, were proposing to unseat Mrs Jane Aukett by rescinding the minute of the meeting that approved her appointment last October.

But the Department for Education wrote to the clerk to the governors, Mr Geoff Hill, saying that such a move would be invalid. In its view, the only meeting at which a vice-chairman could be removed was the first meeting of the school year, the letter said.

When it seemed likely that the move to oust her would still go ahead, Mrs Aukett instructed her solicitor to threaten both the education authority and individual governors with legal action. This had the effect of persuading the governors to agree not to pursue the motion at a recent special meeting, although eight governors said they would follow the authority’s advice on the matter.

On the day of the meeting, the department’s advice was backed up by a faxed letter from Robin Squire, junior education minister, saying there should be no changes to committees or their terms of reference while Mr Bond’s position was under consideration.

The governors then went on to approve a series of changes effectively restricting the powers of the head, David Hampson, who had been the prime mover behind the plan to opt out.

Mr Bond has no political affiliation but had been a local authority appointee to the governing body for 10 years and chairman of governors for four. He opposed grant-maintained status when it was first raised four years ago, but supported it this year because, with senior staff at the school, he wanted more capital investment and greater freedom for the school to manage its own resources.

His removal in March was officially done on the grounds that he had prevented the clerk to the governors from attending a meeting of the governing body.

But the county’s ruling Labour group was known to be angry at Mr Bond’s support for opting out and was concerned it would lose control of one of its largest and most successful comprehensives. No secondary schools have opted out in Humberside since grant-maintained status was introduced six years ago.

After parents at the school voted against opting out, Maxwell Bird, chairman of the education committee, called on both Mr Bond and Mr Hampson to “consider their positions”.

Although it is understood the DFE had advised that no new chairman of governors be appointed until a decision was reached on Mr Bond, the governors appointed another local authority appointee, Peter Morris, at the end of April. Mr Morris, who is the immediate past-chairman of the National Association of Governors and Managers, had opposed the school’s attempt to opt out.

This saga is the second involving Humberside and a school governing body which is currently under investigation by the Department for Education. Mrs Jennifer Watson, formerly deputy head of Sydney Smith School, was suspended and later sacked by the governing body after she had gathered evidence on allegations that caretakers were making claims for work not done. The dismissal has yet to be confirmed as the DFE is looking into complaints about the composition of the governors’ disciplinary panel. And early last year the Local Government Ombudsman upheld a complaint of maladministration from the former chair of Sydney Smith, Ray Webster, after Humberside refused to re-run a parent governor election in which the school issued one ballot paper per child, rather than one per parent.

Humberside County Council will be abolished next March and North East Lincs will assume responsibility for education in Grimsby. The chairman of the education committee for North East Lincs is Peter Morris.