Laws, acts of the parliament and the cabinet, presidential decrees, and acts of the Crimean parliament may be abrogated by the Constitutional Court, should they be found to violate the constitution. Other normative acts are subject to judicial review. The Supreme Court is the main body in the system of courts of general jurisdiction. Local self-government is officially guaranteed. Local councils and city mayors are popularly elected and exercise control over local budgets. The heads of regional and district administrations are appointed by the President in accordance with the proposals of the Prime Minister. This system virtually requires an agreement between the President and the Prime Minister, and has in the past led to problems, such as when President Yushchenko exploited a perceived loophole by appointing so-called 'temporarily acting' officers, instead of actual governors or local leaders, thus evading the need to seek a compromise with the Prime Minister. This practice was controversial and was subject to Constitutional Court review. Ukraine has many political parties, many of which have tiny memberships and are unknown to the general public. Small parties often join in multi-party coalitions (electoral blocs) for the purpose of participating in parliamentary elections. The courts enjoy legal, financial and constitutional freedom guaranteed by Ukrainian law since 2002. Judges are largely well protected from dismissal (except in the instance of gross misconduct). Court justices are appointed by presidential decree for an initial period of five years, after which Ukraine's Supreme Council confirms their positions for life. Although there are still problems, the system is considered to have been much improved since Ukraine's independence in 1991. The Supreme Court is regarded as an independent and impartial body, and has on several occasions ruled against the Ukrainian government. The World Justice Project ranks Ukraine 66 out of 99 countries surveyed in its annual Rule of Law Index. Prosecutors in Ukraine have greater powers than in most European countries, and according to the European Commission for Democracy through Law 'the role and functions of the Prosecutor's Office is not in accordance with Council of Europe standards". The criminal judicial system maintains an average conviction rate of over 99%, equal to the conviction rate of the Soviet Union, with suspects often being incarcerated for long periods before trial. On 24 March 2010, President Yanukovych formed an expert group to make recommendations how to "clean up the current mess and adopt a law on court organization". One day later, he stated "We can no longer disgrace our country with such a court system." The criminal judicial system and the prison system of Ukraine remain quite punitive. Since 1 January 2010 it has been permissible to hold court proceedings in Russian by mutual consent of the parties.