Five law lords will consider evidence from three previous verdicts and rule whether the women, members of the Scottish Secondary Teachers' Association, are entitled to make a claim under the Equal Pay Act 1970. If they win, they might - just - be able to claim back pay of more than Pounds 20,000. Some may receive considerably more, others less, depending on local circumstances.
An estimated 500 teachers across Scotland are awaiting the outcome after lodging claims with industrial tribunals. Financially stretched councils are acutely aware that millions of pounds might have to be conjured up from somewhere, possibly at the cost of teachers' jobs.
The union lost in the Court of Session, Scotland's highest court, after Strathclyde's 12 successor council's appealed against defeats at an industrial tribunal in Glasgow and the employment appeal tribunal in Edinburgh. Now it is appealing to the Lords and is being backed financially by the Equal Opportunities Commission. Eminent silks do not come cheaply and the women's brief is David Pannick, QC.
The women cling to the opinion that they, and many others like them, have been unjustly treated for their commitment to expanding children's education. They are claiming pay parity with principal teachers for running departments, although they were never officially appointed as head.
Their case stems from the 1990 tribunal victory of Dorothy Tedman, a Carluke High mathematics teacher, who won a payment from Strathclyde for running a computing department which had no principal teacher. The result opened the floodgates and if the councils knew then what they know now, they might have challenged the Tedman verdict all the way.
Instead, "Wallace versus Strathclyde and its statutory successors" will make legal history. Kathleen Wallace, senior teacher of religious education at Vale of Leven Academy, Alexandria, and wife of Tom Wallace, the association's former salaries convener, has run the RE department since 1986, requisitioning materials, dealing with enquiries, and teaching Standard grade and Higher courses, with all that involves in terms of administration. But there is still no principal teacher in a department with two and a bit teachers.
Mrs Wallace is adamant the case should continue. "We have been exploited by the authorities and there are three such situations at Vale of Leven. It has not been about money, it is about fairness. We are not a collection of greedy, grasping women. If the case stops others being exploited, it will have been worth it."
Eileen Miller, senior teacher of geography and modern studies at Thomas Muir High, Bishopbriggs, says: "You do not come this far and drop it. There was a principle because the local authorities were getting people to run departments at a cheap rate."
Mrs Miller set up the modern studies department in 1987 and there is still no principal teacher, although the subject is popular. An assistant headteacher takes official responsibility. "I felt I was doing the work and I had two PT colleagues earning Pounds 5,000 more than me for doing the same thing," she complains.
Margaret Milton, now principal teacher music at Smithycroft Secondary, Glasgow, was at St Thomas of Aquinas Secondary as an assistant principal when she raised her claim. She built the department from a low base, administered seven instrumental instructors and one other member of staff. "If there is a subject, it should have a principal teacher," she believes.
"The case was to acknowledge the subject and the status. The main thing is that the practice is still happening. Assistant principal teachers and senior teachers are running departments," Mrs Milton states.
Linda Hall, now principal teacher computing at Trinity High, Renfrew, says that unpromoted teachers were invited to implement Standard grade and Higher courses as computing grew quickly in the late 1980s. Margaret Taggart, principal teacher computing at St Margaret's High, Airdire, observes: "We were responding to a demand from pupils and parents who were asking for computing in the curriculum. There are still departments where there was a PT and now there is an APT in charge."
Linda Park, principal teacher computing at Brannock High, Motherwell, was at Lanark Grammar in 1988 when she was asked by the head to take over computing, a new department. She was given the principal teacher's time allowance but no pay and rejects accusations that staff took on duties as a way of climbing the promotional ladder.
"Money did not enter into it at the beginning. You did it because you loved the subject and had masses of children attracted to it. You would never have said, 'I'm withdrawing my labour'. It was never a money issue," she says.
Mrs Park believes it was the stubbornness of Strathclyde in refusing to acknowledge the situation that prompted the court action. "There is a real sense of injustice," she maintains.
In court, the SSTA used an equal pay loophole to argue that unpromoted women running departments should be paid the same as male principal teachers, provided they were doing like work. The councils countered that they had not discriminated on grounds of sex and that the case should not have been brought under equal pay legislation. It was a regrading issue, they said. The Court of Session upheld that view last year.
The Glasgow tribunal that began in March 1994 and took almost a year is described by the teachers as "an experience" and it has been left to union lawyers to fight the subsequent cases. Mrs Park, who has had strong support from men teachers contends: "Morally, I feel we won. Politically, we cannot win because of the financial implications."
Even if the law lords were to spring a surprise by overturning the Court of Session verdict, the nine teachers know they are unlikely to receive wads of notes in their Christmas stocking. There would be other legal technicalities to overcome, including the amount of backdating and levels of interest and whether councils would be within spending guidelines by authorising payments.
All 500 cases, many of them male, including 350 in the former Strathclyde area, would also have to be proven individually. Councils will not roll over. As Mrs Miller mused: "The mills of justice grind exceedingly slowly."
COMMENT, PAGE 19