e) The right to a defence or a hearing and due process of law 376. The EDRS should guarantee the right to a defence or to a hearing on a challenge both to the complainant and to the person or body complained against. This includes both the opportunity to make their arguments and the obligation on the EDRB to hear and study them. The EDRS must ensure that evidence supporting or refuting the challenge is offered and produced by the two sides to the case, and that the EDRB has a corresponding obligation to weigh that evidence and explain why it considers that it is or is not relevant or effective at establishing the facts (see chapter 7, section 5). All procedures should be guided by the principle of equality of the parties. In general, a distinction is drawn between: (a) the party that files the challenge, which has the standing, or is entitled, to do so (see chapter 7, section 3); (b) the respondent, which, because it is generally an action or decision of the EMB that is being challenged, is the authority in charge of the EMB (other possibilities include a political party whose leadership issued a decision); and (c) third parties, if they have a right to be heard. Several systems provide for an interested third party – another political party or candidate who has an interest that is incompatible with that of the party bringing the challenge but is interested in the outcome – to bring a challenge. In some EDRSs (and in most common law countries) the contention is directly between the political parties or candidates, and not between the party affected and the administrative agency (generally the EMB) whose act or decision is being challenged. 377. The electoral law should expressly establish the requirements, including on standing and legal status, for a challenge to be admissible. Frivolous, vexatious or malicious challenges may thus be excluded and possibly even sanctioned. The EDRB should notify all interested parties in writing of its decision on whether the challenge is or is not admissible, and its reasons should be well founded and well reasoned. Box 6.15. Challenges to the results of national-level elections and referendums: France Andrew Ellis In France, challenges to the results of national-level elections and of referendums are dealt with by the Constitutional Council. When a complaint is received, the Council assigns the case to one of its sections. If the complaint is found to be inadmissible or the alleged irregularities cannot change the result of the election, the case is dismissed. Otherwise, in the case of elections, the Council asks the person elected to respond to the complaint. In addition, the responsible section of the Council may itself demand documents and conduct further investigations. When this process is completed, the 128