Officers FAQ 4
What is the effect of a mayoral veto when the common council action being vetoed is negative in nature? For example, what is the effect of the mayor vetoing a council's denial of a liquor license or a council decision against adopting a particular ordinance?
Although it is not entirely clear whether the veto can be used in this situation, Wis. Stat. sec. 62.09(8) gives the mayor "veto power as to all acts of the council, except such as to which it is expressly or by necessary implication otherwise provided." While the mayoral veto is usually used with regard to affirmative legislation, occasionally it is used following a negative action. It is unclear what the legal effect of a mayoral veto is on negative legislation - whether the veto is merely an expression of the mayor's disagreement with the council's action or whether it has the effect of nullifying the council action unless the council overrides the veto.
There is no Wisconsin legal authority addressing this issue. However, the question sometimes arises whether the mayor's veto of a negative action results in the affirmative. Although no Wisconsin law addresses this issue either, the League believes it is clear that the mayor's veto cannot cause the affirmative. For example, the mayor's veto of the council's denial of the liquor license does not cause the license to be granted. Similarly, it does not cause the ordinance that was defeated to be enacted.