Headteachers and governors of GM schools will have to preside over mass redundancies as the funding system which allowed them to employ extra staff is shaken up.
The 755 GM schools who replied to the survey - 64 per cent of the total - predicted they would have to lose 1,164 staff. This extrapolates to 1,800 across the sector.
The Government intends to create three new categories of school - community, aided and foundation. Consultation on the categories closed this week and legislation to set them up and abolish the GM sector is expected to take effect by April 1999.
Job losses and other upheavals predicted by the survey suggest that the Government could face unwelcome publicity as it pushes through the changes to put all state schools on an equal financial footing.
Pauline Latham, chairman of the Grant-Maintained Schools Advisory Committee, believed the job losses would be higher. "There is going to be a significant number of people losing their jobs."
The GM sector was a flagship Tory reform intended to liberate schools from their local councils. Just eight GM schools told The TES that they were prepared to return to town hall control, while almost half said that they expected recriminations from their former councils.
Fifty-one headteachers said they would quit over the changes.
Graham Lane, education chair of the Local Government Association, is meeting GM heads on Monday in an attempt to dispel their fears of a backlash.
"I am shocked at the level of fear among GM heads," he said. "I am going to make it clear that recriminations are not acceptable and if Labour members are involved I will make sure disciplinary action is taken."
The survey also showed that the Anglican and Catholic Churches face serious problems as they attempt to retain control of their GM schools. At least a fifth want to leave the diocese in order to remain independent of the local authority and a further quarter are undecided.
Ministers intended GM aided schools to choose the new aided category, whereby the Church could maintain some influence with the bishops appointing 11 out of the 21 governors at a secondary school.
The high level of GM aided schools indicating they will go for the new foundation status - the nearest equivalent to opting out - is already alarming church authorities. Cardinal Hume, head of the Roman Catholics in England, has said he wants them to become aided.
Margaret Smart, director of the Catholic Education Service, warned the future of some Catholic schools was at risk.
"If schools go down the foundation route only 25 per cent of the governing body will be foundation governors which will weaken the influence of the church," she said.
"If the Catholic nature of the school is eroded one has to ask whether they can remain as Catholic schools. This is not a threat, it is a reality."
Stephen Dorrell, shadow education secretary, said: "These figures are very striking evidence of the extent to which schools that have gone GM believed the status represented an important development. The figures reveal that the change of status will lead to a shift of resources out of schools and into the bureaucracy.
"GM schools will resist not just the change of status but also the change of relationship."
l Nearly 250 employees could lose their jobs when the GM funding quango is wound up in 1999. School standards minister Stephen Byers has said their future employment cannot be guaranteed. The 49 staff loaned to the Funding Agency for Schools from Government departments will return to them.