It was only due to the intervention of the Natioanl Association of Schoolmasters Union of Women Teachers (NASUWT) which accurately analysed that a boycott would only be legally defensible on grounds of workload, ad which would, therefore, have to apply to all the subjects, which led to the results you describe.
The NASUWT was criticised at the time by many organisations, including the National Association for the Teaching of English, for destroying an alleged consensus, that any boycott should be limited to that subject and that it should take place on philosophical rather than workload grounds. As the court verdicts later confirmed, such an approach would have led to defeat and the unions would have been liable to substantial damages.
Nigel de Gruchy
General secretary, NASUWT
5 King Street, London WC2