polar bear wrote:Can you contact union official on a Sunday
Why not if you have their phone number.
It all depends on the reason for needing to contact them.
No point in calling them on a Sunday if the Manager wants to change your break - I'd send them a text as a heads up and see them at work.
But if you have suffered a death in the family and can't contact a manager, then I don't think anyone would be upset at that.
To answer the basic question. There is neither a right to contact them on a Sunday, but then there is neither a ban.