His departure this summer, to take up a headship in Nottinghamshire, leaves the governors searching for their fourth principal in 12 months.
Chris Williams left last summer while Graham Horsewood, appointed as executive principal to help the schoo
l meet the challenges of the reorganisation of secondary education in Melton and the Vale of Belvoir, left last autumn just a few months into his role.
To help manage the changes County Hall appointed a vastly experienced educational adviser, Edmund Gabbani, last autumn. He splits his time between the school and working with the council on the reorganisation and it insists its plans for King Edward VII, as part of the £45m shake-up, are on track.
But Rob Watson, a former governor at the school, claimed Mr Gibson's resignation 'highlights once again the dire situation at King Edward VII'.
He said: "This is added to a poor inspection report in March from the School Improvement Unit of the county council, disappointing exam results last term, confirmation from the local authority it will not be building a new school on the site, the announcement of 39 letters of redundancy and the forecast of around 300 pupils for the whole of the high school in September of next year."
County Hall declined to comment specifically on Mr Gibson's departure leaving it to the school to issue a statement which paints a rather different picture.
As reported in the Melton Times the authority recently submitted plans for the borough's exciting new £13m post-16 centre, due to open in 2011 on the Sarson Centre site, and says it is making progress on plans for the 11 to 16 school based on the modern Harris Building and existing school premises.
Mr Gibson has spent five years at King Edward VII and will be moving to Retford Oaks High School from the start of the new school year in September.
He said: "I have enjoyed my time at King Edward VII and have had the privilege of working with some of the most dedicated and professional people, all of whom are committed to supporting the learning of young people in Melton.
"Our students are a credit to themselves, their parents and the school and I wish them all the best for the future. It is, however, time for me to move on and I am looking forward to taking on a new challenge."
David Davies, chairman of governors, added: "I am delighted for Dave that he has been successful in securing a permanent headship. It is another success for the school that he has developed the leadership abilities which have enabled him to get this post. As a school we aim to develop the abilities of both staff and students and I regard this as yet another success for the school."
He added the governors have already began the process of building on 'the excellent leadership of Mr Gibson and current members of the senior management team'.
"Parents should be reassured the established high standards of leadership within the school will continue to ensure the future success of King Edward VII students and wider community."
