have to say i would rather have a cs than a supply teacher cover my classes - our faculty cs will deliver whatever lesson i leave, including practicals: supply teachers rarely will do unless booked for long term supply. Also they know the kids and rarely have any different discipline issues to the rest of the teaching staff.
To revert to the OP the guidelines i've been sent by the NASUWT appear to differ, i've cut and pasted a section in below as I can't seem toi find it on the website to link to :
Staff employed to provide cover
? If an NASUWT supply teacher is contracted-in to do supply work on the day of a strike by other unions, they will be subject to deployment by the headteacher and the NASUWT would not advise them to refuse to cover even if they are deployed to cover a class/group affected by the industrial action.
? If an NASUWT supply teacher is covering the timetable of someone on long-term absence, e.g. sickness or maternity leave, they should work their normal timetable.
? If an NASUWT member has a contract which is wholly to provide cover for absence, they will be subject to deployment by the headteacher and the NASUWT would advise them to provide cover even if it is for a class/group affected by the industrial action.
? If an NASUWT member has a contract of which only part is to provide cover for absence and they are asked to cover during their timetabled time for cover, the NASUWT would advise them to cover. If, however, they are asked to cover during their other timetabled time because the class/group they would normally have been timetabled to teach is not in school, they should decline to be reallocated to another class or group for the purposes of covering for a teacher who is taking industrial action.