There are two main factors to take into account in this regard: on the one hand, the freedom of political parties has to be ensured; on the other, internal democracy is key to their work. In this context, there are two models in Europe concerning the regulation of political parties. Some states have a liberal view and do not enact detailed rules on political parties. Other states tend to regulate the functioning of political parties, and sometimes go into great detail. In the latter case, states should find a proper balance between the freedom of political parties and the requirement for internal democracy.