Sharron Goode, principal of Unity College, has left the Church of England school after originally giving notice that she would leave at the end of the school year.

One teacher from Unity, who asked not to be named, said Mrs Goode's departure had come as a surprise to staff. He said: "She has been here for 20 odd years and has been good."

The announcement came only days after the Archbishop of York praised the college for being a "model" secondary school.

Mrs Goode told school governors about two months ago she would resign in the summer, but has now decided to take up a position at the Diocese of Peterborough.

Joe Burns, the interim principal at Unity, said: "It was Sharron Goode's intention to leave Unity College at the end of this academic year.

"However she has been offered a secondment to work for the Diocese of Peterborough, looking at development of Church of England Schools in new areas, and Unity's governing body has agreed to release her early to take up this position."

Mrs Goode had worked hard to tackle a string of problems at the former Trinity School, in Kingsley, since it became a secondary school.

It was originally placed in special measures by Ofsted only to be given the slightly less serious Notice to Improve after Mrs Goode blamed extensive building work for disruption to education.

It has been in the inadequate category for more than three years.