In dream terms a spiritual veto – the right to forbid an action – can be experienced in many ways: a straightforward refusal, a withdrawal of approval or a definite denial of rights.
Psychological / emotional perspective: In emotional terms a veto happens in dreams when we have a strongly felt reason for not agreeing to a particular course of action. Sometimes it is not until the dream action occurs that we realize the strength of our feeling.
Material aspects: When or if an action offends in real life against a code of behaviour, we may find our dreams directing us to operate the right of veto.
Dreams of a veto reflect your instinct and negative feelings about a situation. Your dream is reminding you that you always that the right to say no. See Boundary.