THE controversial secular ethics trial starting today in NSW schools is a policy of the previous premier and does not have full support from the Keneally government, says the NSW head of Catholic scripture teachers.

''We got the great feeling that this was one of Nathan Rees's personal babies,'' said Robert Haddad, the director of the Confraternity of Christian Doctrine for the Archdiocese of Sydney.

During a meeting with representatives from the office of the Education Minister, Verity Firth, last month, Mr Haddad ''really got the feeling that these guys were lamenting that they had to carry the can for someone else's policy'', he said.

Ms Firth confirmed the trial would begin today, denying it had been delayed. She insisted the trial, which has been attacked by religious lobby groups, was ''very important to me as minister''.

The Catholic Bishop of Wollongong, Peter Ingham, speaking on behalf of the Catholic bishops of NSW, said the decision to conduct the probationary program was made by Mr Rees just before he was replaced as premier.

Mr Haddad said Baulkham Hills North, where all parents were told about the ethics classes, not just those whose children had opted out of scripture, was ''an example of the abuse that will inevitably follow. There was a 47 per cent uptake [of the ethics class] and that eroded into the number of students who are going to SRE, so our case is borne out,'' he said.

Children would always choose what was ''new and exciting'', sometimes to their detriment. ''Medicine is not always going to taste sweet,'' he said.

On March 17 religious educators including Mr Haddad, Bishop Ingham and the head of the Inter-Church Commission on Religious Education in Schools, Ann-Maree Whenman, spoke to ministerial staffers, seeking an assurance that religious educators would be part of the trial's evaluation.