By Seonag Mackinnon
BBC Scotland Education Correspondent
The education secretary has said some teachers may have to leave the profession because they are not up to the job.
Mike Russell was responding to concerns about the requirement, under the new curriculum for excellence, for staff to develop more lessons for themselves and make less use of text books and worksheets.
Staff are being encouraged to develop more lessons themselves
Mr Russell said: "At the end of the day, there are some people who will not make it and we need to be quite clear these are people who should not be in our classrooms."
Rejecting any suggestion that poor skills were widespread, Ronnie Smith, general secretary of the EIS teaching union, said later: "It's never been easier to sack a teacher."
He added: "The competence of teachers is 'umbilically' connected to the level of resources and continuous professional development (training)."
Speaking at a meeting of the parliament's education committee, Mr Russell said the curriculum had evolved from the existing one but indicated it would be challenging.
"It is actually in world terms a rather revolutionary approach," he said.
He added "I have an absolute commitment to the highest standards of teaching in Scotland and I want to see that constantly in place.
"And if despite help, despite support, all the things that we should do as good employers, yes there is a reality that some people should be doing something else. "
Margaret Smith, the Liberal Democrat's education spokeswoman, said head teachers were worried that a minority of staff would struggle to adapt.
"It's absolutely crucial for this curriculum to work that we have good teachers," she said.
"I've been put into classrooms by head teachers who have known the teacher they're showing me is not up to standard.
"Head teachers have a real difficulty with this."
Mr Russell said local authorities had been reluctant to take action in the past about teachers whose talents probably lie outside the profession.
Last year, for the first time, the General Teaching Council of Scotland barred a teacher on the grounds of competence.
The education secretary said lesson plans, resources and training courses were in the pipeline but said ultimately they might not be enough.
Responding to teachers' complaints that the new curriculum was ill-defined and that schools were ill-prepared, the education secretary said sample lessons were being distributed and in-service courses set up to provide help for teachers seeking to upgrade their skills.
Ronnie Smith, of the EIS, said head teachers needed to act if a teacher was letting down pupils.
"What on earth are they doing if they don't take action?, he said.
"It could be seen as a dereliction of duty if they acquiesce in allowing these people to still teach in our schools."