Political parties in representative democracies are so important that democratic states are often described as "party states". Among the most important functions of political parties are:

• They constitute the basic channels for the development, compilation and representation of political views and interests in the electoral processes;
• They contribute to the selection of political elites and rulers;
• They formulate programs and ideologies that compete in the political arena, combine interests and ideological preferences, and
• Finally, they can function as a counterweight to governmental decisions.
  
  

Given the critical role of political parties in pluralistic electoral systems,” The legal framework should ensure that all political parties and candidates are able to compete in elections on the basis of equal treatment before the law.”[i] 

For the purpose of this topic, attention will be directed to the fundamental elements of the legal framework governing political parties that are related to their participation in the electoral process. The level of political party involvement in the electoral process varies according to the electoral system and the level of election. In parliamentary elections, political parties often have a near monopoly over the candidate nomination and in most cases the fact that a list is supported by a political party is crucial for the identification. In presidential elections, focus is obviously placed on candidates but their party affiliation usually plays an important role.

Political parties can also be defined as voluntary groups of citizens formed with the aim of contributing to the determination of State policy (or at the respective territorial level) through the shaping of citizens’ political will, the nomination and support of candidates, the development of political programs and any other activity oriented towards the achievement of these goals.

International law (Article 22 of the ICCPR), “guarantees the right to freedom of association, which includes the right to establish and operate political parties.”[ii]  The establishment and functioning of political parties in a democratic state should be free, but they may be subject to certain typical requirements (such as the elaboration and submission of party statutes to a public registry or to the electoral authority) and substantial requirements, such as the obligation to conform to democratic principles respecting the Constitution, the laws and the democratic system.

Special requirements may also be imposed on political parties when some of their activities are funded or subsidized by the State and considering the fact that political parties are a vehicle for access to elected office. Certain legal orders have also created mechanisms to ensure that the structure and operation of political parties are democratic.  However, “Any limitations to the rights to freedom of association, expression and assembly must be prescribed by law and necessary in a democratic society.”[iii] As such, it is up to the legal framework to protect against undue restrictions and to entrench due process to ensure that restrictions are not applied in an arbitrary fashion.[iv]

Political parties may have very different structures. In contemporary democratic systems, there are two main types of political parties: small parties marked by liberal ideas that originate from the French and American revolutions and big labor parties that have emerged since the second half of the nineteenth century.

Participation in democratic elections should be open to all political parties that share democratic values and incorporate democratic rules with regard to both their internal functioning and objectives and external functioning. Faithfulness to the democratic system should not be conceived, however, as absolute acceptance of existing laws and policies. Nothing prevents political parties from advocating for legal or constitutional reforms, provided that they respect the valid procedures prescribed by law on access to government or legal and constitutional reforms.

Most systems impose certain minimum requirements for the recognition of political parties. In general, these requirements aim to ensure a minimum standard of publication of the establishment of political parties through registration in a public record or other similar publication depending on the country, and to determine the democratic nature of their internal and external functioning.

Political parties are usually registered in a public register under the authority of the administrative or electoral authorities. In a pluralistic system, this should be a formal requirement aiming to prevent a situation where the name or symbol of a new party is confused with the name or symbol of any previously registered party.  In addition, political parties should submit their statutes which should prove that the party pursues lawful purposes through democratic means and democratic internal procedures. 

However, the purpose of registration must not be to limit or put up barriers to the registration of political parties; “A genuine election requires an open and inclusive registration process for political parties and candidates from across the political spectrum, contributing to presentation of a real choice to the electorate.”[v]  For example, registration is often accompanied by the requirement of a monetary deposit and/or the collection of signatures in support of the application.  If a monetary deposit is required it should be justifiable and of a reasonable amount and the deposit should be returned on fulfilling clearly set out criteria such as receiving a given percentage of the vote. In the case of signatures, an application should not be dismissed because a certain number or percentage of invalid signatures but rather the party should be permitted to submit additional valid signatures of support.[vi]

Neither should de-registration be taken lightly.  In order to respect the fundamental rights of association, expression and assembly and to avoid speculation and abuse, a review of party registration should be restricted to only those cases of serious violations of the law and under clear and processes.[vii] 

There is a constant debate regarding the extent of the restrictions that a democratic system should impose on the functioning of associations and political parties that advocate against the democratic system. There are, of course, different solutions which must take into account the powers and the roots of each system.  Nevertheless, it is essential to ensure the application of the rule of law and democratic principles. This cannot be achieved by imposing restrictions on the freedom of expression, but by regulating the exercise of organized political activities related to electoral competition.  In some countries, such as Mexico, the provisions regarding political parties are included not only in the legislation but also in the Constitution, given the great importance of their role in the political life.

When party systems and democracies have reached a certain level of maturity, stricter requirements are imposed with regard to the internal functioning of the political groups seeking access to government or to other elected offices. Thus, it is usually required that the internal functioning of political parties is governed by open and transparent rules. The most common requirement is that the leaders and the program of each political party are selected on the basis of democratic procedures open to all party members. This situation most often arises in mature party systems where there are well-established political parties able to implement these principles. Certainly, the election of party leaders is largely determined by the candidates’ popularity and leadership skills. Nevertheless, regardless of the factors that determine the decision of party members, they should be given the opportunity to make a democratic decision which includes the possibility to seek redress through the judiciary or other independent monitoring bodies in case their rights have not been respected. As regards the external activities of political  parties, there are two aspects that should be regulated; the instruments  used in their general political action and the specific requirements and rules of conduct that govern their participation in the different electoral processes.

The financing of political parties consists of the economic resources at the disposal of the party and for the achievement of their mission as set or regulated in the law. In certain countries, such as most Latin American countries, the regulation of political party funding has constitutional status. Codes or specific laws governing political party financing form a complementary legal framework providing for controls and prohibitions. Party financing can be divided in two main categories: funding related to the parties’ maintenance, which is used to cover their regular expenses, and funding in relation to the electoral processes, which is used to cover the expenses of their election campaign.  Political financing is considered in more depth in a subsequent section.