discretion of the executive but is regulated by law emanating from parliament33 and covers not only the legal basis for the existence of a “tribunal,” but also compliance by the tribunal with the particular rules that govern it34 and the tribunal’s composition in each case.35 52. In the case at hand, the Commission notes that the Constitution established the jurisdiction of the Chamber of Deputies to impeach justices of the Supreme Court for improper performance of their duties, in which case they had to present the articles of impeachment to the Senate, which is responsible for holding the impeachment trial and deciding on the removal of Supreme Court justices. 53. Nevertheless, the Commission notes that on November 22, 2003, after the Chamber of Deputies had formulated the articles of impeachment against the alleged victims, the Senate issued Resolution No. 122, which established not only the Rules of Procedure for the Handling of the Impeachment Trial but procedural rules for this particular impeachment trial, with a substantive impact on the exercise of a defense, as well as other aspects related to due process guarantees. Specifically, in these rules of procedure the Senate determined, among other things: i) that challenges to the disciplinary body would not be admitted; ii) that the Senate’s ruling could not be appealed; iii) that each defendant’s presentation of his defense could not last more than three hours; iv) that the articles of impeachment would be delivered to the alleged victims on Wednesday, November 26, 2003, and they would have until Monday, December 1, 2003—in other words, two business days—to prepare their defense and offer their evidence. 54. The Commission deems that the incorporation of ad hoc procedural rules such as those indicated above, through rules of procedure applicable to the alleged victims’ specific case, when the proceeding had already begun with the articles of impeachment, violates the right established in Article 8(1) of the Convention, which holds that both the disciplinary authority and the procedure to be followed should be previously established by law. This constitutes a guarantee which provides the necessary legal certainty of knowing beforehand what the competent authority will be and thus the scope and manner in which its competence will be exercised, and which seeks to protect the right of defense. This is even more important considering that this case involves sanction proceedings against judges, bearing in mind the reinforced guarantees of tenure that apply to those who hold such positions, in order to safeguard their independence. 55. In view of the foregoing, the Commission concludes that the Paraguayan State violated the right to a hearing by a competent authority by means of previously established procedures, established in Article 8(1) of the American Convention, in connection with the obligations established in Articles 1(1) and 2 therein, to the detriment of Bonifacio Ríos Ávalos and Carlos Fernández Gadea. 3. The right to an impartial judge 56. The IACHR calls to mind that the guarantee of impartiality is wholly applicable to impeachment proceedings that involve the removal of judges, taking into account that the decisive aspect for determining the respective guarantees and their scope is the punitive nature of the power being exercised by the authority in question. The guarantee of impartiality implies that the members of a disciplinary body “have no direct interest in, a pre-established viewpoint on, or a preference for one of the parties, and that they are not involved in the controversy.”36 57. The Inter-American Court has indicated that the recusal of judges is a means to protect the right to a hearing by an impartial body. It gives parties the right to move for the exclusion of a judge when, regardless of the personal conduct of the questioned judge, there are demonstrable facts or convincing elements that may lead to reasonable fears or legitimate suspicions of partiality toward the person. A recusal would prevent the judge’s decision from being seen as motivated by reasons alien to the law and thus prevent ECHR, Case of Biagioli v. San Marino, Third section, Application 8162-13, July 8, 2014, para. 74. ECHR, Case of Sokurenko and Strygun v. Ukraine. Applications 29458/04 and 29465/04, Judgment of November 12, 2006, paras. 24 and following. 35 See Guide on Article 6 of the European Convention on Human Rights,: Right to a fair trial (civil limb), Updated to August 31, 2018, paras. 174 and following. 36 I/A Court. H.R., Case of Palamara Iribarne vs. Chile. Merits, Reparations and Costs. Judgment of November 22, 2005. Series C No. 135, para. 146. 33 34 14