From August, no teacher will have more than 23.5 hours of pupil contact time, and from 2006 the maximum will be 22.5. Since pupils are in class for 25 hours, alternative arrangements are required for their teaching and it is the exact nature of the arrangements that is exercising primary heads.
Recent years have seen increased flexibility due to setting, visiting specialists and modern languages. Our primary 7 pupils are not alone in meeting five or six teachers each week apart from their class teacher. But the class teacher has always been the anchor - liaising, listening, explaining, clarifying, sympathising, remonstrating, as necessary.
From August the main teacher takes no part in the life of the class beyond her timetabled maximum contact. Darren's illicit acquisition of football stickers or Emily's timely fainting fit will be none of her business. Nor will the planning, implementation, assessment and reporting of the work undertaken by the relief - now called "McCrone" - teacher whose relationship with the class will, inevitably, be restricted.
The demise of the all-seeing, all-knowing class teacher ends a tradition whose origins are lost in the mists of time. Certainly, the Greeks and Romans knew the advantages. The idea of passing on knowledge, skills and culture and developing children's experience through a close relationship with a learned and mature adult has been the mainstay of all civilised societies.
The privilege, responsibility and delight of the class teacher is to have picked up the mantle of the magister or the dominie as the undisputed leader of pupils. She directs their formal learning. Her key is the detailed knowledge of each child which she gains during her extended time with them each day and which allows her to adapt the curriculum in a thousand small and unnoticed ways to suit the perceptions of each pupil.
The class teacher uses formative assessment and personal learning techniques all the time. Usually she is too modest to mention this, which is why our education leaders' current obsessions are presented as something new.
The way in which class teachers stay in our adult memories indicates their importance as guides to a wider world in our early years. Try the memory game for yourself. We had Miss Matthias in primary 5. She dressed only in black - in mourning for her father, we heard. Her facial wrinkles suggested a crabbed old age to match her crabbed temperament. In primary 7, Mrs Foster spoke to us like grown-ups. Perhaps she was a closet progressive. On one occasion she had us move our desks into groups for a discussion. We were uneasy. This was the 1950s and no one expected us to have opinions.
The experiment was not repeated, so it must have been a failure. That suited us.
Then there was Miss Kelly, who was never our teacher but was admired from afar. She wore lipstick and bright clothes and drove a scarlet Hillman Minx. My belief that she was a rebel demands that staffroom opinion condemned her as a shameless hussy.
McCrone is right. Teachers need more time for preparation and assessment, but the forthcoming organisation will be difficult with too many unknown factors in play. Effective timetabling and regular reviews will be required.
Most parents are in the dark but those who are informed are not worried.
They see this as a chance to harness teachers' strengths to improve children's learning. Just as long as they realise that, for the children, we need to retain the best elements of the class teacher.
Brian Toner is headteacher of St John's primary in Perth.