This is a difficult one @Rosemarie99
Do these current guests break the current regulations in Scotland in terms of exceeding the number of households?
I don’t think you can ask the guests to cancel if by doing so they would lose money i.e. the Airbnb fee.
Perhaps you could ask Airbnb to do a mutual no penalty cancellation?
i would also update your listing and house rules to indicate max guests and households so that if guests book outside of this you can ask them to cancel penalty free within first 48 hoyrs of booking.