Q: I have been asked to attend a meeting at lunchtime. Can I refuse?

Yes, indeed!

'A teacher must be allowed one break of reasonable length between the hours of 12 noon and 2pm.'

So, if at your school the lunch break for teachers is between 1pm and 2pm, then you have a statutory right to that time for your lunch.

Asking some teachers to have a shorter lunch break than others amounts to potential discrimination.

You cannot be directed to perform any school related task during your lunch-break.