The proposed dismantling of the grant-maintained system is forcing some heads to consider opting out of their schools and even the profession.

Of the 755 responding to the survey, 51 (7 per cent) said they would leave after the abolition of their sector. Of these, 11 are planning to retire, though a few are going early to avoid possible confrontations when their school returns to the local authority.

The findings show many headteachers fear personal recriminations from the education authority. One grammar-school head from the north of England said: “I would like to remain in post but I have received veiled threats.”

Another, also from the North, said: “I was targetted in a difficult second ballot (over opting out) and subjected to a dirty tricks campaign. I have no intention of working as headteacher under the education authority.”

A head in the South-east said: “I may have to apply for other jobs. They are already rubbing their hands with glee and making alarming noises.”

Some are already looking for posts outside their authority, or planning to defect to the independent sector. “If it goes back to where it was I shall be looking for headships outside of the state system. I am yet to be convinced that this Government knows how to achieve excellence in education,” said one.

Others would rather abandon their schools than watch what they perceive to be the strides of the past few years undermined by the change of status.

The head of a Kent secondary school said: “All the oomph will go out of me. I dread it. We will go back light years. We are falling into an abyss. The Government is naive and policy-making on the hoof doesn’t work.”

Another grammar-school head said: “I think it unlikely that I will stay in post for very long after the change of status. I do not relish the task of making colleagues redundant or dismantling successful innovations.

“Like many GM colleagues, I am concerned about the powers which authorities are seeking with regard to monitoring comments on the head’s performance and the fairness with which these will be used.”

Some heads believe they will be perceived as a threat by LEA officers because of the finance and management skills they have acquired.

A Kent headteacher said: “It is possible that many GM heads could be better strategic planners than the officers of the LEA to which their schools are returned. This could cause problems including a possible further exodus of experienced heads.”

Others are resigned to an uncertain fate. “I’m too young to go, too young to die. I expect I’ll stay - if they’ll have me,” said an Essex head.