they are carried out in keeping with the law. In such cases, the responsibility has been entrusted to public servants (as in Uruguay), or directly to citizens chosen randomly and provided with training (as in Indonesia and Mexico). Experience in some systems has shown that the involvement of public servants gives rise to suspicions that they may be biased in their actions in favour of the party in government. In some countries not being a public servant is a requirement for serving as a polling officer. Other arrangements include, but are not limited to, the EMB appointing the polling officials, and the involvement of civil society organizations. 469. Similarly, the procedure for the placement of polling stations seeks to ensure that the locations are determined according to clear and objective rules, that they are as geographically close to the voters as possible in order to encourage the greatest possible voter access and participation, and that their size and physical condition allows for normal operations and they can be subject to oversight on election day. The practical arrangements should be such as to impede any violation of the secret ballot and guarantee impartiality: the owners or those legally responsible for the building or premises may not have any political ties to parties or candidates or, in some countries, the government. In addition, some electoral laws establish that there must be adequate access for voters with special needs or disabilities, that the polling stations must be divided by gender, that account must be taken of the boundaries of electoral districts, that the area of a polling station must be fully within the limits of a single electoral district, and that no polling station serves a disproportionate number of voters such that it is impossible to process them all on election day. 470. The EMB’s decisions on the composition of the polling station staff and the placement of polling stations are likely to be subject to review before the EDRB to ensure that they are in line with the constitutional and statutory framework. Actions related to election campaigns 471. The various EDR systems offer different mechanisms for ensuring that electoral campaigns are in line with the constitutional and statutory legal framework, with regard to both the contenders (political parties and candidates) and third parties that may be involved (for example the media). The aim is to ensure a level playing field for the electoral contest. The actions of both contenders and others can give rise to electoral challenges. 472. Electoral campaigns can be times of high tension. They may give rise not only to electoral challenges and prosecution of allegations of electoral process-related offences or infractions but also to breaches of the general law, for example, in the field of public order. Offences of this kind are not dealt with in this Handbook. 158