A referendum on the treaty establishing a Constitution for Europe was held in Spain on 20 February 2005. The consultative referendum on ratification of the proposed Constitution of the European Union was approved by 81.8% of voters, although turnout was just 41.8%, the lowest since the end of the Franco era.
A constitutional referendum was held in France on 5 May 1946. Voters were asked whether they approved of a new draft Constitution proposed by the Constituent Assembly elected in 1945.
A constitutional referendum was held in France on 13 October 1946. Voters were asked whether they approved of a new constitution proposed by the Constituent Assembly elected in June. Unlike the May referendum, which saw a previous constitutional proposal rejected, the new constitution was accepted by 53.2% of voters, and brought the French Fourth Republic into existence. Voter turnout was 67.6%.
A constitutional referendum was held in France on 28 September 1958. Voters were asked whether they approved of the adoption of a constitution for the French Fifth Republic written by Charles de Gaulle. It was overwhelmingly approved, with 82.6% in favour. Voter turnout was 84.9% in Metropolitan France and 79.8% overall.
A referendum was held in France on 20 and 21 December 1851. Voters were asked whether they approved of the continuation of the authority of Louis Napoléon Bonaparte and to delegate the powers required to produce a new constitution. It was approved by 92% of voters with an 81.7% turnout.
A non-binding referendum on the Single European Act was held in Denmark on 27 February 1986. It was approved by 56.2% of voters, with a voter participation of 75.4%.
A constitutional referendum was held in Poland on 25 May 1997. Voters were asked whether they approved of a new constitution. It was narrowly approved, with 53.5% voting in favour. Voter turnout was just 42.9%. Although the 1995 Referendum Act stated that a 50% turnout was required to validate the referendum, the Supreme Court ruled on 15 July that the constitution could be introduced.
A constitutional referendum was held in Bulgaria on 16 May 1971. Voters were asked whether they approved of a new constitution, whose first article noted the "leading role" of the Communist Party. The result was reportedly 99.7% in favour, with a voter turnout of 99.7%.
A referendum on a new constitution and citizenship was held in Estonia on 28 June 1992. Voters were asked whether they approved of the new constitution drawn up by the Constitutional Assembly and extending suffrage to people registered as citizens. The new constitution was approved by 91.9% of voters, whilst the suffrage extension was rejected by 53.5%. Voter turnout was 66.8% for the constitution question and 66.7% for the suffrage question.
An advisory referendum on joining the European Union was held in Finland on 16 October 1994. 56.9% of voters approved of the proposal, with a voter turnout of 70.8%. Due to having its own customs jurisdiction, a separate referendum was held in the Åland Islands a month later, and was also approved.
A constitutional referendum was held in Romania on 8 December 1991. The new constitution was approved by 79.1% of voters.
A constitutional referendum was held in Switzerland on 19 April 1874. The new constitution was approved by 63.2% of voters and a majority of cantons. It gave more responsibilities and powers to the federal government.
Two referendums were held in Switzerland in 1879. A federal law on subsidies for railways in the Alps was passed by 70.7% of voters on 19 January, whilst a referendum on the death penalty on 18 May was passed by 52.5% of voters and a majority of cantons.
Three referendums were held in Switzerland in 1882. Two were held on 30 July on copyright law and measures against epidemics, both of which were rejected. The third was held on 26 November on executing article 27 of the federal constitution, and was rejected by 64.9% of voters.
Two referendums were held in Switzerland in 1887. The first was held on 15 May, asking voters whether they approved of a federal law on spirits, and was approved by 65.9% of voters. The second was held on 10 July, asking voters whether they approved of an amendment made to article 64 of the federal constitution, and was approved by 77.9% of voters and 20.5 cantons.
A referendum on accident and health insurance was held in Switzerland on 2 October 1890. Voters were asked whether they approved of a federal resolution on amending the constitution with regards to accident and health insurance. It was approved by a majority of voters and cantons.
A referendum on copyright was held in Switzerland on 19 March 1905. Voters were asked whether they approved of a federal resolution on revising article 64 of the constitution, defining the protection rights of inventors. It was approved by 70.4% of voters and a majority of cantons.
A referendum on disease control was held in Switzerland on 4 May 1913. Voters were asked whether they approved of amending two articles of the constitution, 31 II, lit d and 69, which covered the control of human and animal diseases. It was approved by a majority of voters and cantons.
A referendum on a war tax was held in Switzerland on 6 June 1915. Voters were asked whether they approved of amending the constitution to introduce a one-off war tax. It was approved by a large majority of voters and all cantons, the first time a referendum had been passed in every canton.
Five referendums were held in Switzerland in 1970. The first was held on 1 February on a federal resolution on the domestic sugar market, and was approved by voters. The second was held on 7 June on a popular initiative "against foreign infiltration", and was rejected by voters. The third and fourth were held on 27 September on an amendment to the Swiss Federal Constitution regarding promoting gymnastics and sports, which was approved, and a popular initiative on the "right to habitation and expansion of family protection", which was rejected. The fifth was held on 15 November on an amendment to the federal financial order, and was approved by voters.
