The quorum to do business will be regulated by the rules of procedure. ARTICLE 33 The National Assembly and its committees may require the presence of the National Chancellor and of any National Minister. The National Chancellor, the National Ministers, and Commissioners designated by them, have the right to be present at the sittings of the National Assembly and of its committees. The States are entitled to send their plenipotentiaries to these sittings to submit the views of their Cabinets on matters under consideration. At their request the representatives of the Cabinets shall be heard during the deliberations, and the representatives of the National Cabinet shall be heard even outside the regular order of business. They are subject to the authority of the presiding officer in matters of order. ARTICLE 34 The National Assembly has the right, and, on proposal of one-fifth of its members, the duty to appoint committees of investigation. These committees, in public sittings, inquire into the evidence which they, or the proponents, consider necessary. The public may be excluded by a two-thirds vote of the committee of investigation. The rules of procedure regulate the proceedings of the committee and determine the number of its members. The judicial and administrative authorities are required to comply with requests by these committees for information, and the record of the authorities shall on request be submitted to them. The provisions of the code of criminal procedure apply as far as is suitable to the inquiries of these committees and of the authorities assisting them, but the secrecy of letter and other post, telegraph, and telephone services will remain inviolate. ARTICLE 35 The National Assembly appoints a Standing Committee on foreign affairs which may also act outside of the sittings of the National Assembly and after its expiration or dissolution until a new National Assembly convenes. Its sittings are not public, unless the committee by a two-thirds vote otherwise provides. The National Assembly also appoints a Standing Committee for the protection of the rights of the representatives of the People against the National Cabinet during a recess and after the expiration of the term for which it was elected. These committees have the rights of committees of investigation. ARTICLE 36 No member of the National Assembly or of a State Assembly shall at any time whatsoever be subject to any judicial or disciplinary prosecution or be held responsible outside of the House to which he belongs on account of his vote or his opinions uttered in the performance of his duty. ARTICLE 37 No member of the National Assembly or of a State Assembly shall during the session, without the consent of the House to which he belongs, be subject to investigation or arrest on account of any punishable offence, unless he is caught in the act, or apprehended not later than the following day.