The act of opening a procedure for selecting State contractors is necessarily a general one, as it is an invitation to offer, without a specific recipient. That is why it is striking that in the recent jurisprudential evolution, some pronouncements of the Council of State seem to point out that once offers have been submitted to the public entity, the nature of the opening act is transformed, to become an act of a particular nature, which submits the revocation to the authorization of those interested in it. This article reviews those decisions and proposes an own analysis criterion. In our opinion, if the public contractor concludes that continuing with a contracting process is against the Constitution or the law, or that it contradicts public or social interest, or that it causes an unjustified grievance to a person, it must be able to revoke motivated without asking for the consent of the interested parties. What is the point of requiring the consent of the eventual bidders, or the best bidder, to protect these superior values? How can the interest that such bidders have in concluding a contract be privileged, over the public interest? We believe, then, that the requirement of having the prior and express consent, either of the best proponent or of all the bidders, as derived from some recent decisions of the Council of State, in practice makes the revocation of the opening act infeasible. and it affects theprotection of the general interest itself, which is ultimately the justification for any revocation of a general administrative act. This conclusion, of course, is not intended to be an open space for arbitrariness, because the revocation of the general administrative act of opening is not and could not be, outside the control of legality.