Higher Still is back on course for a staggered start next June after the Scottish Secondary Teachers' Association called off its short-lived boycott and joined multi-party talks on implementing the post-16 reforms.
The union, with around a third of secondary staff, shadowed the Educational Institute of Scotland which two weeks ago backed away from industrial action.
The final go-ahead for staged implementation came at a meeting of the Higher Still liaison group on Monday when broad criteria for phasing subjects were agreed by the Government, local authorities and teacher associations. Douglas Osler, senior chief inspector, described it as a "unique" agreement.
A Scottish Office circular spells out what rephasing will mean in individual schools and departments and includes a comfort message for teachers about standards HM Inspectorate will expect.
It offers guidance on bi-level and multi-level teaching, internal assessment, reassessment and staff development. A statement from the Scottish Qualifications Authority completes the package.
Talks will now take place between unions and education directors to thrash out local implementation details. They have until the end of January to submit plans for each school and subject department's reforms.
Ministers concede the new Higher will be delayed for a further year in some departments, pushing back the start for a fourth time. Delays may be expected in the eight subjects where there has been significant revision of the syllabus, but ministers expect "substantial take-up". Any department ready to go should not be stopped, Mr Osler said.
All levels will be available from next summer and are due to be implemented over the next three to five years as originally intended.
"Any delay of one year should only take place where teachers or lecturers are genuinely unable to implement them in 1999." Mr Osler said.
"This is a deal which enables those who are ready to go from next summer as planned. It phases the implementation in a way which makes certain that the Higher courses will be available across a two-year period," he added.
Philip Banks, HMI responsible for Higher Still, insisted courses would proceed without any further syllabus changes. "There will be no change in English or any other subject," he said at a Scottish Office launch.
Mr Osler offered further reassurance about organising S5 and S6 classes. No teacher would normally be expected to find more than two levels in one classroom, although small schools or departments could be more flexible.
In answering a key union complaint, the Scottish Office circular states:
"HMI would be critical of situations where teachers were required to teach a range of student abilities for which they were unprepared."
It also backs "simple and practicable" record keeping but Mr Osler said internal assessment would remain a vital element. Students who fail a unit would only be expected to do one re-assessment.
In a further sop, the Inspectorate has agreed to review local authorities' staff development plans.
Ronnie Smith, EIS general secretary, called for every teacher and lecturer to be involved in phasing the new Higher. "Only the individual department really knows whether a subject in an individual school or college is likely to be ready for implementation in June 1999," he said.
David Eaglesham, SSTA general secretary, said: "We are beginning to see assurances turn into reality. We are confident these will address the key issues on which we have been pressing."
The Headteachers' Association of Scotland welcomed the devolving of phasing and said it should be a strategy that applied to other initiatives.
* Ian McCalman, former convener of the finance and general purposes of the EIS, is being challenged by Willie Hart, Glasgow local secretary, for the post. Mr McCalman resigned after the executive council overturned his committee's decision to join Higher Still talks. The executive committee later rescinded its boycott.
HIGHER STILL: THE MILESTONES
March 27 1990 Howie committee inquiry announced into upper secondary education.
March 5 1992 Howie committee reports.
March 3 1994 Ian Lang, Secretary of State, responds in Higher Still : Opportunity for All, planning to introduce the system from August 1997.
April 29 1994 Educational Institute of Scotland describes the timescale as "fantasy".
May 12 1994 The first Higher Still newsletter pledges "alterations to existing courses will be kept to the minimum."
Jan 1995 Mary Pirie takes up post as head of the Higher Still Development Unit.
Aug 2 1995 Michael Forsyth, Secretary of State, announces a year's delay in implementation to August 1998.
Aug 1995 Specialist subject groups propose framework for Higher Still subjects and courses.
Sept-Dec 1995 Some 200 seminars held to brief 8,500 staff; 1,500 individual written responses to Higher Still consultation.
Feb 13 1996 Raymond Robertson, Education Minister, offers EIS reassurances.
Feb 11 1997 Headteachers' Association of Scotland calls for another year's delay.
May 14 1997 Association of Directors of Education asks for delay.
May 23 1997 Brian Wilson, Education Minister, announces a year's postponement to August 1999.
Oct 31 1997 TESS reports on English teachers' Higher Still "mutiny".
Nov 24 1997 EIS calls for "immediate and urgent review" of Higher Still assessment.
Jan 24 1998 EIS says "self-phasing" by secondary schools is the key to delivering Higher Still.
Feb 5 1998 Wilson agrees to reduce internal assessment for Higher Still English.
Feb 24 1998 Ian McCalman, EIS president, warns that Higher Still "would have to be scaled down to match the reality of what was possible."
June 12 1998 Wilson announces two extra training days.
Sept 10 1998 Helen Liddell, Education MInister, unveils Pounds 24 million to introduce Higher Still over four years - Pounds 7,500 per school this session.
Sept 14 1998 Liddell writes to reassure secondary heads.
Sept 18 1998 EIS reverses leadership recommendation and orders immediate ballot on a Higher Still boycott.
Oct 7 1998 EIS meets Liddell and Donald Dewar, Secretary of State.
Nov 3 1998 Liddell offers liaison group to oversee phasing in of Higher Still as well as assurances on funding and multi-level teaching.
Nov 5 1998 EIS ballot produces 86 per cent support for a boycott, on a 61 per cent turnout.
Nov 20 1998 EIS executive council rejects olive branches, orders boycott to proceed and appoints "group of five" to negotiate with Liddell and local authorities.
Dec 1 1998 Scottish Secondary Teachers' Association produces 78 per cent vote for a boycott, on a 59 per cent turnout.
Dec 1 1998 EIS starts boycott.
Dec 4 1998 EIS agrees to join liaison group and suspends boycott.
Dec 5 1998 SSTA council confirms boycott.
Dec 14 1998 SSTA boycott begins.
Dec 15 1998 Liaison group announces agreed criteria for local decision-making on phasing in the new Higher by August 2000.
Dec 17 1998 SSTA lifts boycott.