I returned to work 4 days a week and my employers said that I would have to go to 5 days a week after 6 weeks. Agreed to it but am finding 4 days too hard already so asked to stay on 4 days but have been told I cant as they need me to work 5. Their reason is that both my colleagues are off on maternity and being covered by temps who arent experienced enough to do the work they need me to do. Does anyone know if this is a good enough reason legally to refuse me flexible hours?