Agreement to Official Rules: Participation in the Giveaway constitutes entrant's full and unconditional agreement to and acceptance of these Official Rules and the decisions of the Sponsor, which are finalandbinding.
Entrants agree to be bound by the terms of these official rules and by the decisions of Sponsor, which are finalandbinding on all matters pertaining to this contest.
It might be argued - it is being argued - that ending the Union is a much bigger step and thus would require a binding popular verdict upon the final outcome, not simply pre-negotiation consent.