Key recommendations of the Clywch inquiry into child abuse look set to be challenged by teacher unions defending their members against malicious allegations.
The National Union of Teachers Cymru is opposed to plans for new tribunals chaired by lawyers to hear serious cases against school staff accused of abusing pupils.
And UCAC, the Welsh-medium teachers' union, is concerned that records of investigations into teachers will be kept for years and passed on to other agencies - even if teachers are cleared of the allegations.
The unions and other agencies are due to meet with Assembly officials next week to discuss the proposals.
Peter Clarke, the children's commissioner, has proposed the tribunals because he believes governors and school managers find it difficult to investigate serious allegations against colleagues.
In the Clywch report, into how drama teacher John Owen sexually and physically abused pupils at Ysgol Gyfun Rhydfelen, Pontypridd, Mr Clarke concluded that the school's governors had been prevented from investigating by council officials.
But even if they had acted, they would have found it difficult to do so in "the independent manner required", because Owen was well-known to them and a powerful member of the community.
But Gethin Lewis, secretary of the National Union of Teachers Cymru, fears the tribunals will "cause more concerns, more delays and become more litigious" than the current system of local investigations by governor disciplinary committees.
He wants to see the job given to local education authorities, or consideration given to introducing council-based experts to support and advise governing bodies facing serious allegations against a member of staff.
A team of 25 such co-ordinators was introduced in England in 2001 following the case of Marjorie Evans, the head of St Mary's junior school, Caldicot, who was suspended for 18 months over accusations she slapped a 10-year-old pupil. They are still in place but were never introduced in Wales.
Mr Lewis said: "Before going to expensive tribunals with lawyers fighting cases, there might be a middle road. We should be looking at having people to advise governing bodies where there are these occasional, difficult cases.
"We welcomed the children's commissioner's report and shared with him the shock of what happened at Rhydfelen. We want a solution that protects children but also protects people working with them from malicious allegations."
Rex Phillips, senior regional official for the National Association of Schoolmasters Union of Women Teachers Cymru, said it was keeping an open mind about the tribunals.
"There is this tension over the ability of governors to act impartially in these matters. But there is far more rigour in the system now than there was in Owen's day."
UCAC supports the tribunals, because of the difficulty headteachers and governors in small schools face investigating colleagues. But general secretary Moelwen Gwyndaf is concerned that another recommendation may lead to investigations of teachers being kept and passed on to other agencies - even if they have been cleared.
Mr Clarke has recommended that the Welsh Assembly government should issue guidance by next summer on how investigations are recorded on school staff files, and what information can be shared between agencies where there are allegations of child abuse - "whether or not findings have been made".
Owen resigned from his school post in 1991 but was able to carry on working with children because the allegations made against him were not shared with other organisations. He worked on theatre productions for the Urdd Gobaith Cymru (Welsh language youth movement) and Pam Fi Duw, the S4C children's series he wrote and produced, before committing suicide in 2001 after criminal charges were laid against him.
Ms Gwyndaf said: "We are concerned about this because of false allegations.
"We have had situations where parents, after going to the police with a complaint, have decided not to press charges.
"They just wanted to scare the teacher. But it's there on the police record. The situation then is that the teacher doesn't have a chance to clear their name properly.
"It is difficult to get the right balance because we do have to look after children, but we also have to ensure fairness for everyone."