The revolution in school timetabling is being led by a handful of local education authorities, which hope to have their plans in place for September 2000.
They believe the educational advantages of change outweigh the complications of being out of step with the rest of the country.
It is argued shorter summer holidays and more even terms would reduce summer learning loss and allow for modular curriculum planning, improved assessment, and a more regular pace of learning.
East Sussex councillors met today to consider proposals for a five-term year, while the London borough of Newham is already consulting schools about similar changes. Aberdeen, Tower Hamlets and at least nine education action zones are also interested in reforming the school year.
But the National Association of Schoolmasters Union of Women Teachers has condemned the moves. General secretary Nigel de Gruchy said it was a bad time to consider changing teachers' working patterns, given the Government's Green Paper on pay and conditions. "It's not very helpful for education authorities to be discussing plans which are going to upset teachers because they will involve alterations to the working year," he said.
A spokeswoman for the National Union of Teachers said reducing the summer holidays - one of the big attractions of teaching, according to surveys - would not help in the battle for more recruits to the profession.
However, a Department for Education and Employment spokesman said ministers were interested in changes - if the aim is to raise standards.
East Sussex's proposals envisage a four-week summer break, with eight-week terms separated by 14-day holidays. Teachers' terms and conditions would remain unchanged, as would the three annual resignation dates - although this would lead to schools coping with staff joining and leaving mid-term.
Matt Dunkley, assistant education director, led the working group that came up with the proposals. He says, "Educationally, five eight-week blocks allow for a modular curriculum and regular assessment points. The evidence is that pupils stay on task for those eight weeks, and the two-week breaks allow more time for recovery - teachers and children say they feel less tired."