The Vidovdan Constitution was the first constitution of the Kingdom of Serbs, Croats and Slovenes. It was approved by the Constitutional Assembly on June 28, 1921 despite the opposition boycotting the vote. The Constitution is named after the feast of St. Vitus (Vidovdan), a Serbian holiday. The Constitution required a simple majority to pass. Out of 419 representatives, 223 voted for, 35 voted against and 161 abstained.

The Constitution was in effect until King Alexander proclaimed his January 6th Dictatorship

January 6th Dictatorship

The January 6th Dictatorship was a royal dictatorship established in the Kingdom of Serbs, Croats and Slovenes by King Alexander...

 on that date in 1929.

For

• Democratic Party
  Democratic Party (Yugoslavia)
  The Yugoslav Democratic Party, State Party of Serbian, Croatian and Slovene Democrats and Democratic Party was the name of a series of social-liberal political parties that existed in succession in the State of Slovenes, Croats and Serbs, the Kingdom of Serbs, Croats and Slovenes, and the Kingdom...
  
  
• People's Radical Party
  People's Radical Party
  The People's Radical Party of Serbia was a political party formed on January 8, 1881, which was active in the Kingdom of Serbia and the Kingdom of Serbs, Croats and Slovenes...
  
  
• Yugoslav Muslim Organization
  Yugoslav Muslim Organization
  Yugoslav Muslim Organization was a Bosnian Muslim political party in the Kingdom of Serbs, Croats and Slovenes. It was founded in Sarajevo on February 16, 1919 and was led by Mehmed Spaho. In election campaigns the JMO did mobilize on religious slogans rather than Bosnian nationality, calling...
  
  
• Alliance of Agrarians
  Agrarian Party (Yugoslavia)
  The Agrarian Party was a political party within the Kingdom of Serbs, Croats and Slovenes and later the Kingdom of Yugoslavia. It was formed in 1919....
  
  
• Džemijet
  Džemijet
  Džemijet was a political party of Kosovo Albanians and Sandžak-Muslims within the Kingdom of Serbs, Croats, and Slovenes. It was formed in 1919. The party participated in the Kingdom's 1920 elections and 1923 elections....
  
  

Boycotted

• Communist Party of Yugoslavia - left assembly in June
• Croatian Republican Peasant Party - boycotted assembly since 1920 elections
• Slovenian People's Party
  Slovenian People's Party
  The Slovenian People's Party is a rural-based conservative political party in Slovenia. Formed in 1988 under the name of Slovenian Peasant Union as the first non-Communist political organization in Yugoslavia, it merged with the Slovene Christian Democrats to form the present-day party in 2000...
  
   - left assembly in June
• Croatian People's Party - left assembly in June
• Croatian Union - left assembly in May

Croatian Republican Peasant Party

The Croatian Republican Peasant Party adopted its Constitution of the neutral peasant republic of Croatia in Zagreb

Zagreb

Zagreb is the capital and the largest city of the Republic of Croatia. It is in the northwest of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb lies at an elevation of approximately above sea level. According to the last official census, Zagreb's city...

 on April 1, 1921.

Croatian Union

The Croatian Union had proposed a confederation of the kingdom into six entities:

1. Serbia
2. Croatia
3. Montenegro
4. Bosnia and Herzegovina
5. Vojvodina
6. Slovenia

Aftermath

The viability of the constitution dominated the 1923 parliamentary elections

Kingdom of Serbs, Croats and Slovenes parliamentary election, 1923

The 1923 election in the Kingdom of Serbs, Croats and Slovenes for the National Assembly took place on March 18, 1923. The seats were divided up by the political borders which existed before the Kingdom's formation and distributed using the population statistics of 1910.According to a TIME Magazine...

.

The Croatian Peasant Party

Croatian Peasant Party

The Croatian Peasant Party is a center and socially conservative political party in Croatia.-Austria-Hungary:The Croatian People's Peasant Party was formed on December 22, 1904 by Antun Radić along with his brother Stjepan Radić. The party contested elections for the first time in the Kingdom of...

 did not accept the legitimacy of the constitution. After the 1925 elections, the party was offered to enter the government by Nikola Pašić

Nikola Pašic

Nikola P. Pašić was a Serbian and Yugoslav politician and diplomat, the most important Serbian political figure for almost 40 years, leader of the People's Radical Party who, among other posts, was twice a mayor of Belgrade...

. The Croatian Peasant Party accepted the offer, agreeing to recognize the constitution. This led to the release of the party's leader Stjepan Radić

Stjepan Radic

Stjepan Radić was a Croatian politician and the founder of the Croatian Peasant Party in 1905. Radić is credited with galvanizing the peasantry of Croatia into a viable political force...

from prison, along with other party officials.