Michael Chapman, 44, left Cambridge Education Associates, which manages the scheme, on Friday to take up a headship at Driffield School, an East Riding comprehensive, on Monday.

Mr Chapman, who was appointed “professional leader” of threshold assessment in September 1999, denied frustration with the project and said he had decided to leave because he missed teaching.

His post at CEA, which this year received pound;12 million to manage the system of allowing experienced teachers to apply for a pound;2,000 pay rise, is likely to remain vacant until January.

Mr Chapman said: “People may find it hard to believe but I have missed teaching ever since I left my previous job as head of Birley School in Sheffield.

“I missed the interaction with staff and pupils and the feeling of making a difference in a community.

“When I took up the CEA post it was always my intention to return to teaching. It has very much been a vocation for me and my heart was always in education at the sharp end.

“I felt that, having overseen the implementation of threshold assessment, I had fulfilled the role I was appointed for and it was just a matter of waiting for a vacancy at the right school.”

He had taken the decision to leave his Sheffield-based post just before Christmas when the Driffield headship came up.

Mr Chapman was unwilling to discuss problems with the scheme.

“All things considered, the first year went extremely well. In schools that have implemented performance management effectively it has made a phenomenal change to teaching and learning,” he said.

Mr Chapman, an Oxford graduate who began teaching at the age of 22, will also to teach history at the 1,800-pupil school.