Grant-maintained and aided schools have called for a "vindictiveness ombudsman" to protect them when the GM sector is scrapped, writes Clare Dean.
They fear they will lose out in the allocation of capital grants and that GM staff will be discriminated against when they look for new jobs. They also worry about the misuse of target setting and early warning systems by authorities.
The Association of Grant-Maintained and Aided Schools said ministers should not underestimate the profound distrust of local authorities felt by many GM schools.
"There is a strong risk of LEA triumphalism which will do the cause of raising standards no good," it said.
The AGMAS said there was an urgent case for establishing a "vindictiveness ombudsman", an independent person to whom former GM schools and staff could appeal.
"For the future framework of education to be a success, LEAs have to be aware that they have to live down their past."
Opted-out sector representatives this week met Graham Lane, education chair of the Local Government Association, to discuss fears.
Mr Lane pledged disciplinary action against Labour members if they took part in any backlash.