“ Any constitutional reform will require the approval by absolute majority of the members of the Congress and of the Senate. The Senate will consider the text previously approved by the Congress, and if it is not accepted in the same terms, the differences will be submitted to a Mixed Commission, under the presidency of he who holds that of the Cortes, and of which will form part the Presidents of the Congress and of the Senate, four Deputies and four Senators, elected by their respective chambers. ”