The co-operation of the Reichsrat is manifested also in its _right of protest_ against the laws enacted by the Reichstag. These laws must in theory be enacted with the express or tacit approval of the Reichsrat, but this provision is not absolute. If, in effect, after the protest of the Reichsrat, no accord is reached between this body and the Reichstag, it devolves upon the President of the Reich to decide whether the project of law will be abandoned by him, or whether he will resort to a referendum against the decision taken by the Reichsrat. If this bill gains the support at the Reichstag of a majority of two-thirds the President has then, in spite of the protest of the Reichsrat, the right to promulgate and to publish the law, without any further vote on it by the Reichstag. But he may also, instead of proceeding to this promulgation, order a referendum, if he does not want to take upon himself the responsibility of deciding this conflict of the Reichstag and the Reichsrat. There are thus two ways of breaking the opposition of the Reichsrat: either the referendum, or else a two-thirds vote for the law on the part of the Reichstag and joined to it the approval of the President. On the other hand, when this majority of two-thirds cannot be assembled in the Reichstag, there are two ways for the opposition in the Reichsrat to become effective. First, the President may remain passive after the protest of the Reichsrat, that is to say, he may not order the referendum. The co-operation of the Reichsrat and of the President in such case weighs more than the decision of the Reichstag which has not been able to rally a majority of two-thirds in its favour. The other way in which a protest of the Reichsrat can become effective is for the referendum to support the objection of the Reichsrat and reject the project voted by the Reichstag.