Extracurricular activities include school teams, music/drama productions and clubs.
Where members have made a professional judgement and have volunteered freely to undertake extracurricular activities and provide extra support for certain pupils, then the Union maintains that this is a matter of personal choice, provided that those involved have not been placed under pressure to do so.
This should not form part of your contract of employment, as it falls outside the scope of those professional responsibilities for which you can be directed, as specified in the STPCD (section 50) (pdf).
In addition, as a voluntary activity, this should not be something against which you are assessed for the purposes of any performance management or appraisal system used by the school.
The NASUWT maintains that any voluntary activities, specifically those for which you attract an additional payment, should be subject to a separate contractual arrangement to that for which you are employed as a teacher.