Councillors on Wednesday agreed to consult parents and teachers about radical restructuring of primaries and secondaries, including a change to the school year.
But plans to transfer the final year of primary to a new lower secondary and establish a separate upper secondary within the same building are almost certain to be challenged.
The most controversial recommendation is for pupils in the lower school - P7 to S3 - to attend in the morning and early afternoon. Older pupils would attend in the afternoons and early evenings.
Equally contentious are plans to reduce the length of the summer holidays to four weeks and move to a four-term year.
"The extended summer holiday period does not assist continuity and learning," officials say.